Environmental history

The city of Machu Picchu was constructed c. 1450 AD, at the height of the Inca Empire. It has commanding views down two valleys and a nearly impassable mountain at its back. There is an ample supply of spring water and enough land for a plentiful food supply. The hillsides leading to it have been terraced to provide farmland for crops, reduce soil erosion, protect against landslides, and create steep slopes to discourage potential invaders.

Environmental history is the study of human interaction with the natural world over time. In contrast to other historical disciplines, it emphasizes the active role nature plays in influencing human affairs. Environmental historians study how humans both shape their environment and are shaped by it.

Environmental history emerged in the United States out of the environmental movement of the 1960s and 1970s, and much of its impetus still stems from present-day global environmental concerns.[1] The field was founded on conservation issues but has broadened in scope to include more general social and scientific history and may deal with cities, population or sustainable development. As all history occurs in the natural world, environmental history tends to focus on particular time-scales, geographic regions, or key themes. It is also a strongly multidisciplinary subject that draws widely on both the humanities and natural science.

The subject matter of environmental history can be divided into three main components.[2] The first, nature itself and its change over time, includes the physical impact of humans on the Earth's land, water, atmosphere and biosphere. The second category, how humans use nature, includes the environmental consequences of increasing population, more effective technology and changing patterns of production and consumption. Other key themes are the transition from nomadic hunter-gatherer communities to settled agriculture in the neolithic revolution, the effects of colonial expansion and settlements, and the environmental and human consequences of the industrial and technological revolutions.[3] Finally, environmental historians study how people think about nature - the way attitudes, beliefs and values influence interaction with nature, especially in the form of myths, religion and science.

Origin of name and early works

Main article: Roderick Nash

In 1967 Roderick Nash published "Wilderness and the American Mind", a work that has become a classic text of early environmental history. In an address to the Organization of American Historians in 1969 (published in 1970) Nash used the expression "environmental history",[4] although 1972 is generally taken as the date when the term was first coined.[5] The 1959 book by Samuel P. Hays, Conservation and the Gospel of Efficiency: The Progressive Conservation Movement, 1890-1920, while being a major contribution to American political history, is now also regarded as a founding document in the field of environmental history. Hays is Professor Emeritus of History at the University of Pittsburgh.[6]


Main article: Historiography

Brief overviews of the field of environmental history have been given by John McNeill in 2003,[7] Richard White in 1985,[8] and J. Donald Hughes in 2006.[9] In 2014 Oxford University Press published a volume of 25 essays entitled The Oxford Handbook of Environmental History. This collection was edited by Andrew C. Isenberg.


There is no universally accepted definition of environmental history. In general terms it is a history that tries to explain why our environment is like it is and how humanity has influenced its current condition, as well as commenting on the problems and opportunities of tomorrow.[10] Donald Worster's widely quoted 1988 definition states: "Environmental history is the interaction between human cultures and the environment in the past."[11]

In 2001 J. Donald Hughes defined the subject as “The study of human relationships through time with the natural communities of which they are a part in order to explain the processes of change that affect that relationship.”[12] and, in 2006, as "... history that seeks understanding of human beings as they have lived, worked and thought in relationship to the rest of nature through the changes brought by time"[13] ... "As a method, environmental history is the use of ecological analysis as a means of understanding human history ... an account of changes in human societies as they relate to changes in the natural environment.[12] Environmental historians are also “interested in what people think about nature, and how they have expressed those ideas in folk religions, popular culture, literature and art.[12] In 2003 McNeill suggested that environmental history was "... the history of the mutual relations between humankind and the rest of nature".[7]

Subject matter

Traditional historical analysis has over time extended its range of study from the activities and influence of a few significant people to a much broader social, political, economic and cultural analysis. Environmental history further broadens the subject matter of conventional history. In 1988, Donald Worster stated that environmental history “attempts to make history more inclusive in its narratives[14] by examining the “role and place of nature in human life”,[15] and in 1993, that “Environmental history explores the ways in which the biophysical world has influenced the course of human history and the ways in which people have thought about and tried to transform their surroundings”.[16] The interdependency of human and environmental factors in the creation of landscapes is expressed through the notion of the cultural landscape. Worster also questioned the scope of the discipline, asking: "We study humans and nature; therefore can anything human or natural be outside our enquiry?"[17]

Environmental history is generally treated as a subfield of history, an established discipline. But some environmental historians challenge this assumption, arguing that while traditional history is human history – the story of people and their institutions,[18] "humans cannot place themselves outside the principles of nature."[19] In this sense environmental history is a version of human history within a larger context, one less dependent on anthropocentrism (even though anthropogenic change is at the center of its narrative).[20]


General view of Funkville in 1864, Oil Creek, Pennsylvania, USA

J. Donald Hughes responded to the view that environmental history is "light on theory" or lacking theoretical structure by viewing the subject through the lens of three "dimensions": nature and culture, history and science, and scale.[21] This advances beyond Worster's recognition of three broad clusters of issues to be addressed by environmental historians although both historians recognize that the emphasis of their categories might vary according to the particular study[22] as, clearly, some studies will concentrate more on society and human affairs and others more on the environment.


Several themes are used to express these historical dimensions. A more traditional historical approach is to analyse the transformation of the globe’s ecology through themes like the separation of man from nature during the neolithic revolution, imperialism and colonial expansion, exploration, agricultural change, the effects of the industrial and technological revolution, and urban expansion. More environmental topics include human impact through influences on forestry, fire, climate change, sustainability and so on. According to Paul Warde, “the increasingly sophisticated history of colonization and migration can take on an environmental aspect, tracing the pathways of ideas and species around the globe and indeed is bringing about an increased use of such analogies and ‘colonial’ understandings of processes within European history.[23] The importance of the colonial enterprise in Africa, the Caribbean and Indian Ocean has been detailed by Richard Grove.[3] Much of the literature consists of case-studies targeted at the global, national and local levels.[24]


Although environmental history can cover billions of years of history over the whole Earth, it can equally concern itself with local scales and brief time periods.[25] Many environmental historians are occupied with local, regional and national histories.[26] Some historians link their subject exclusively to the span of human history – "every time period in human history"[19] while others include the period before human presence on Earth as a legitimate part of the discipline. Ian Simmons's Environmental History of Great Britain covers a period of about 10,000 years. There is a tendency to difference in time scales between natural and social phenomena: the causes of environmental change that stretch back in time may be dealt with socially over a comparatively brief period.[27]

Although at all times environmental influences have extended beyond particular geographic regions and cultures, during the 20th and early 21st centuries anthropogenic environmental change has assumed global proportions, most prominently with climate change but also as a result of settlement, the spread of disease and the globalization of world trade.[28]

History of the subject

Nature preservationist John Muir with US President Theodore Roosevelt (left) on Glacier Point in Yosemite National Park

The questions posed and themes covered by environmental history date back to antiquity: historians have always included the effects of natural phenomena on human affairs.[29] Hippocrates, ancient Greek father of medicine, in his Airs, Waters, Places, asserted that different cultures and human temperaments could be related to the surroundings in which peoples lived.[30] During the Enlightenment there was a rising awareness of the environment as concept and early environmental scientists addressed themes of sustainability via the subjects of natural history and medicine.[31] However, the origins of the subject in its present form are generally traced to the twentieth century.

In 1929 a group of French historians founded the journal Annales, in many ways a forerunner of modern environmental history since it took as its subject matter the reciprocal global influences of the environment and human society. The idea of the impact of the physical environment on civilizations was espoused by this Annales School to describe the long term developments that shape human history[17] by focusing away from political and intellectual history, toward agriculture, demography, and geography. Emmanuel Le Roy Ladurie, a pupil of the Annales School, was the first to really embrace, in the 1950s, environmental history in a more contemporary form.[32] One of the most influential members of the Annales School was Lucien Febvre (1878–1956), whose book A Geographical Introduction to History is now a classic in the field.

The most influential empirical and theoretical work in the subject has been done in the United States where teaching programs first emerged and a generation of trained environmental historians is now active.[23] In the United States environmental history as an independent field of study emerged in the general cultural reassessment and reform of the 1960s and 1970s along with environmentalism, "conservation history",[33] and a gathering awareness of the global scale of some environmental issues. This was in large part a reaction to the way nature was represented in history at the time, which “portrayed the advance of culture and technology as releasing humans from dependence on the natural world and providing them with the means to manage it [and] celebrated human mastery over other forms of life and the natural environment, and expected technological improvement and economic growth to accelerate”.[34] Environmental historians intended to develop a post-colonial historiography that was "more inclusive in its narratives".[14]

Moral and political inspiration

Moral and political inspiration to environmental historians has come from American writers and activists Henry Thoreau (1817 – 1862), John Muir (1838 – 1914), Aldo Leopold (1887 – 1948), and Rachel Carson (1907 – 1964). Environmental history frequently promoted a moral and political agenda although it steadily became a more scholarly enterprise.”[14] Early attempts to define the field were made in the United States by Roderick Nash in “The State of Environmental History” and in other works by frontier historians Frederick Jackson Turner, James Malin, and Walter Prescott Webb who analysed the process of settlement. Their work was expanded by a second generation of more specialized environmental historians such as Alfred Crosby, Samuel P. Hays, Donald Worster, William Cronon, Richard White, Carolyn Merchant, John McNeill, Donald Hughes, Chad Montrie, and Europeans Paul Warde, Sverker Sorlin, Robert A. Lambert, T.C. Smout and Peter Coates.

British Empire

Although environmental history was growing rapidly after 1970, it only reached historians of the British Empire in the 1990s.[35][36][37] Gregory Barton argues that the concept of environmentalism emerged from forestry studies, and emphasizes the British imperial role in that research. He argues that imperial forestry movement in India around 1900 included government reservations, new methods of fire protection, and attention to revenue-producing forest management. The result eased the fight between romantic preservationists and laissez-faire businessmen, thus giving the compromise from which modern environmentalism emerged.[38]

In recent years numerous scholars cited by James Beattie have examined the environmental impact of the Empire.[39] Beinart and Hughes argue that the discovery and commercial or scientific use of new plants was an important concern in the 18th and 19th centuries. The efficient use of rivers through dams and irrigation projects was an expensive but important method of raising agricultural productivity. Searching for more efficient ways of using natural resources, the British moved flora, fauna and commodities around the world, sometimes resulting in ecological disruption and radical environmental change. Imperialism also stimulated more modern attitudes toward nature and subsidized botany and agricultural research.[40] Scholars have used the British Empire to examine the utility of the new concept of eco-cultural networks as a lens for examining interconnected, wide-ranging social and environmental processes.[41]

Current practice

Frontier historian
Frederick Jackson Turner (1861–1932)

In the United States the American Society for Environmental History was founded in 1975 while the first institute devoted specifically to environmental history in Europe was established in 1991, based at the University of St. Andrews in Scotland. In 1986, the Dutch foundation for the history of environment and hygiene Net Werk was founded and publishes four newsletters per year. In the UK the White Horse Press in Cambridge has, since 1995, published the journal Environment and History which aims to bring scholars in the humanities and biological sciences closer together in constructing long and well-founded perspectives on present day environmental problems and a similar publication Tijdschrift voor Ecologische Geschiedenis (Journal for Environmental History) is a combined Flemish-Dutch initiative mainly dealing with topics in the Netherlands and Belgium although it also has an interest in European environmental history. Each issue contains abstracts in English, French and German. In 1999 the Journal was converted into a yearbook for environmental history. In Canada the Network in Canadian History and Environment facilitates the growth of environmental history through numerous workshops and a significant digital infrastructure including their website and podcast.[42]

Communication between European nations is restricted by language difficulties. In April 1999 a meeting was held in Germany to overcome these problems and to co-ordinate environmental history in Europe. This meeting resulted in the creation of the European Society for Environmental History in 1999. Only two years after its establishment, ESEH held its first international conference in St. Andrews, Scotland. Around 120 scholars attended the meeting and 105 papers were presented on topics covering the whole spectrum of environmental history. The conference showed that environmental history is a viable and lively field in Europe and since then ESEH has expanded to over 400 members and continues to grow and attracted international conferences in 2003 and 2005. In 1999 the Centre for Environmental History was established at the University of Stirling. Some history departments at European universities are now offering introductory courses in environmental history and postgraduate courses in Environmental history have been established at the Universities of Nottingham, Stirling and Dundee and more recently a Graduierten Kolleg was created at the University of Göttingen in Germany.[43] In 2009, the Rachel Carson Center for Environment and Society (RCC), an international, interdisciplinary center for research and education in the environmental humanities and social sciences, was founded as a joint initiative of Munich's Ludwig-Maximilians-Universität and the Deutsches Museum, with the generous support of the German Federal Ministry of Education and Research.[44] The Environment & Society Portal (environmentandsociety.org) is the Rachel Carson Center's open access digital archive and publication platform.[45]

Related disciplines

The 77 km long Panama Canal, opened in 1914, connects the Caribbean Sea to the Pacific Ocean, replacing a long and treacherous shipping route passing via the Drake Passage and Cape Horn at the tip of South America. Construction was plagued by problems, including disease (particularly malaria and yellow fever) and landslides. By the time the canal was completed, a total of 27,500 French and American workmen are estimated to have died.

Environmental history prides itself in bridging the gap between the arts and natural sciences although to date the scales weigh on the side of science. A definitive list of related subjects would be lengthy indeed and singling out those for special mention a difficult task. However, those frequently quoted include, historical geography, the history and philosophy of science, history of technology and climate science. On the biological side there is, above all, ecology and historical ecology, but also forestry and especially forest history, archaeology and anthropology. When the subject engages in environmental advocacy it has much in common with environmentalism.

With increasing globalization and the impact of global trade on resource distribution, concern over never-ending economic growth and the many human inequities environmental history is now gaining allies in the fields of ecological and environmental economics.[46][47]

Engagement with sociological thinkers and the humanities is limited but cannot be ignored through the beliefs and ideas that guide human action. This has been seen as the reason for a perceived lack of support from traditional historians.[23]


The subject has a number of areas of lively debate. These include discussion concerning: what subject matter is most appropriate; whether environmental advocacy can detract from scholarly objectivity; standards of professionalism in a subject where much outstanding work has been done by non-historians; the relative contribution of nature and humans in determining the passage of history; the degree of connection with, and acceptance by, other disciplines - but especially mainstream history. For Paul Warde the sheer scale, scope and diffuseness of the environmental history endeavour calls for an analytical toolkit "a range of common issues and questions to push forward collectively" and a "core problem". He sees a lack of "human agency" in its texts and suggest it be written more to act: as a source of information for environmental scientists; incorporation of the notion of risk; a closer analysis of what it is we mean by "environment"; confronting the way environmental history is at odds with the humanities because it emphasises the division between "materialist, and cultural or constructivist explanations for human behaviour".[48]

Global sustainability

Two views of the Earth from space.
Achieving sustainability will enable the Earth to continue supporting human life as we know it. Blue Marble NASA composite images: 2001 (left), 2002 (right)
Main article: Sustainability

Many of the themes of environmental history inevitably examine the circumstances that produced the environmental problems of the present day, a litany of themes that challenge global sustainability including: population, consumerism and materialism, climate change, waste disposal, deforestation and loss of wilderness, industrial agriculture, species extinction, depletion of natural resources, invasive organisms and urban development.[49] The simple message of sustainable use of renewable resources is frequently repeated and early as 1864 George Perkins Marsh was pointing out that the changes we make in the environment may later reduce the environments usefulness to humans so any changes should be made with great care[50] - what we would nowadays call enlightened self-interest. Richard Grove has pointed out that "States will act to prevent environmental degradation only when their economic interests are threatened".[51]


Main article: Advocacy

It is not clear whether environmental history should promote a moral or political agenda. The strong emotions raised by environmentalism, conservation and sustainability can interfere with historical objectivity: polemical tracts and strong advocacy can compromise objectivity and professionalism. Engagement with the political process certainly has its academic perils[52] although accuracy and commitment to the historical method is not necessarily threatened by environmental involvement: environmental historians have a reasonable expectation that their work will inform policy-makers.[53]

Declensionist narratives

Narratives of environmental history tend to be declensionist, that is, accounts of progressive decline under human activity. Thus environmental history, like environmentalism, is perceived as entrenched pessimism, a litany of degeneration, failure, loss, decline and decay often portrayed as proceeding from some halcyon golden age of the past.

Presentism and culpability

Under the accusation of "presentism" it is sometimes claimed that, with its genesis in the late 20th century environmentalism and conservation issues, environmental history is simply a reaction to contemporary problems, an "attempt to read late twentieth century developments and concerns back into past historical periods in which they were not operative, and certainly not conscious to human participants during those times".[54] This is strongly related to the idea of culpability. In environmental debate blame can always be apportioned, but it is more constructive for the future to understand the values and imperatives of the period under discussion so that causes are determined and the context explained.[55] An awareness of presentism can help us to be wary of the easy wisdom of hindsight.

Environmental determinism

Ploughing farmer in ancient Egypt. Mural in the burial chamber of artisan Sennedjem c. 1200 BCE

For some environmental historians "the general conditions of the environment, the scale and arrangement of land and sea, the availability of resources, and the presence or absence of animals available for domestication, and associated organisms and disease vectors, that makes the development of human cultures possible and even predispose the direction of their development"[56] and that "history is inevitably guided by forces that are not of human origin or subject to human choice".[57] This approach has been attributed to American environmental historians Webb and Turner[58] and, more recently to Jared Diamond in his book "Guns, Germs, and Steel", where the presence or absence of disease vectors and resources such as plants and animals that are amenable to domestication that may not only stimulate the development of human culture but even determine, to some extent, the direction of that development. The claim that the path of history has been forged by environmental rather than cultural forces is referred to as environmental determinism while, at the other extreme, is what may be called cultural determinism. An example of cultural determinism would be the view that human influence is so pervasive that the idea of pristine nature has little validity - that there is no way of relating to nature without culture.[59]


Main article: Historical method
Recording historical events

Useful guidance on the process of doing environmental history has been given by Donald Worster,[60] Carolyn Merchant,[61] William Cronon[62] and Ian Simmons.[63] Worster's three core subject areas (the environment itself, human impacts on the environment, and human thought about the environment) are generally taken as a starting point for the student as they encompass many of the different skills required. The tools are those of both history and science with a requirement for fluency in the language of natural science and especially ecology.[64] In fact methodologies and insights from a range of physical and social sciences is required, there seeming to be universal agreement that environmental history is indeed a multidisciplinary subject.

Some Key Works

Seminal works by region

In 2004 a theme issue of Environment and History 10(4) provided an overview of environmental history as practiced in Africa, the Americas, Australia, New Zealand, China and Europe as well as those with global scope. J. Donald Hughes (2006) has also provided a global conspectus of major contributions to the environmental history literature.


African landscape: Lesotho


North and South America

United States


Banaue rice terraces in the Philippines where traditional landraces have been grown for thousands of years



Roman aqueduct and plaza, Segovia, Spain

Australia, New Zealand & Oceania

Polynesian outrigger canoe

United Kingdom


Old and new human uses of the atmosphere

Environmental history, like all historical studies, shares the hope that through an examination of past events it may be possible to forge a more considered future. In particular a greater depth of historical knowledge can inform environmental controversies and guide policy decisions.

The subject continues to provide new perspectives, offering cooperation between scholars with different disciplinary backgrounds and providing an improved historical context to resource and environmental problems. There seems little doubt that, with increasing concern for our environmental future, environmental history will continue along the path of environmental advocacy from which it originated as “human impact on the living systems of the planet bring us no closer to utopia, but instead to a crisis of survival[66] with key themes being population growth, climate change, conflict over environmental policy at different levels of human organization, extinction, biological invasions, the environmental consequences of technology especially biotechnology, the reduced supply of resources - most notably energy, materials and water. Hughes comments that environmental historians “will find themselves increasingly challenged by the need to explain the background of the world market economy and its effects on the global environment. Supranational instrumentalities threaten to overpower conservation in a drive for what is called sustainable development, but which in fact envisions no limits to economic growth”.[67] Hughes also notes that "environmental history is notably absent from nations that most adamantly reject US, or Western influences".[68]

Michael Bess sees the world increasingly permeated by potent technologies in a process he calls “artificialization” which has been accelerating since the 1700s, but at a greatly accelerated rate after 1945. Over the next fifty years, this transformative process stands a good chance of turning our physical world, and our society, upside-down. Environmental historians can “play a vital role in helping humankind to understand the gale-force of artifice that we have unleashed on our planet and on ourselves”.[69]

Against this background “environmental history can give an essential perspective, offering knowledge of the historical process that led to the present situation, give examples of past problems and solutions, and an analysis of the historical forces that must be dealt with[70] or, as expressed by William Cronon, "The viability and success of new human modes of existing within the constraints of the environment and its resources requires both an understanding of the past and an articulation of a new ethic for the future."[71]

Related journals

Key journals in this field include:

See also



Asia & Middle East

Europe and Russia



  1. MacEachern & Turkel 2009, p. xii
  2. Worster 1988, p. 293
  3. 1 2 See Grove 1994
  4. Nash 1970, pp. 249–260
  5. Nash 1972, p. 362
  6. Samuel P. Hays on National Forests and Ecology, History for the Future, WRCT, Pittsburgh
  7. 1 2 McNeill 2003, pp. 5–43
  8. See White 1985
  9. See Hughes 2006
  10. Dovers 1994, p. 4
  11. Worster 1988, p. 289
  12. 1 2 3 Hughes 2001, p. 4
  13. Hughes 2006, p. 1
  14. 1 2 3 Worster 1988, p. 290
  15. Worster 1988, p. 292
  16. Worster 1993, p. 20
  17. 1 2 Worster 1988, p. 306
  18. Dovers 1994, p. 5
  19. 1 2 Hughes 2008, p. 8
  20. Hughes 2008, p. 5
  21. Hughes 2008, p. 3
  22. Worster 1988, pp. 289–308
  23. 1 2 3 See Warde & Sorlin 2007
  24. Hughes 2006, pp. 53–92
  25. See Krech, McNeill & Merchant 2003
  26. Hughes 2006, pp. 53–93
  27. Dovers 1994, p. 14
  28. Hughes 2006, p. 78
  29. Hughes 2006, pp. 18–35
  30. Hughes 2006, p. 21
  31. Eddy, Matthew Daniel (2008). The Language of Mineralogy: John Walker, Chemistry and the Edinburgh Medical School 1750-1800. Ashgate.
  32. See McNeill 2003
  33. Adam Rome "Conservation, Preservation, and Environmental Activism: A Survey of the Historical Literature". Retrieved 2010-8-8.
  34. Hughes 2001, p. 5
  35. Robin Winks, ed. (1999). The Oxford History of the British Empire: Volume V: Historiography. pp. 664–65.
  36. Madhav Gadgil and Ramachandra Guha, This fissured land: an ecological history of India (1993).
  37. John M. MacKenzie, The empire of nature: Hunting, conservation and British Imperialism (1997).
  38. Gregory Barton, "Empire forestry and the origins of environmentalism." Journal of Historical Geography 27#4 (2001): 529-552.
  39. James Beattie, "Recent Themes in the Environmental History of the British Empire," History Compass (Feb 2012) 10#2 pp 129-139
  40. William Beinart and Lotte Hughes. Environment and empire (2007)
  41. James Beattie, Edward Melillo, and Emily O'Gorman. "Rethinking the British Empire through eco-cultural networks: materialist-cultural environmental history, relational connections and agency." Environment and History 20#4 (2014): 561-575.
  42. "NiCHE Website". Retrieved June 2011. Check date values in: |access-date= (help)
  43. What is Environmental History? K. Jan Oosthoek. Retrieved 2010-8-8.
  44. "RCC Website". Retrieved Feb 2016. Check date values in: |access-date= (help)
  45. "Environment & Society Portal Website". Retrieved Feb 2016. Check date values in: |access-date= (help)
  46. Bess 2005, pp. 30–109
  47. Martinez-Alier & Schandle 2002, pp. 175–176
  48. See Warde & Sorlin 2007, pp. 107–130
  49. Hughes 2006, pp. 2–3
  50. See Marsh 1864, p. 15
  51. Grove 1992, pp. 42–47
  52. Opie 1983, pp. 8–16
  53. See Worster 1993
  54. Hughes 2006, pp. 98–99
  55. Dovers 1994, pp. 14–16
  56. Hughes 2006, p. 5
  57. Hughes 2006, p. 97
  58. White 2001, p. 55
  59. See Cronon 1995
  60. Worster 1988, pp. 289–387
  61. See Merchant 2002
  62. Cronon 1993, pp. 1347–1376
  63. See Simmons 1993
  64. Hughes 2008, p. 6
  65. http://www.tesisenxarxa.net/TDX-0620105-134124/
  66. Hughes 2006, p. 125
  67. Hughes 2006, pp. 92–93
  68. Hughes 2006, p. 75
  69. Bess 2005b
  70. Hughes 2006, p. 126
  71. "See Cronon quote here". Searchworks.stanford.edu. Retrieved 2014-01-03.

External links

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