Stephen of Liège
- This article is not about the Benedictine Stephen of Liège (d. 1061)
He was an abbot of Lobbes and canon of Metz Cathedral. His In Festi Sanctisissimae Trinitatis, an office for the feast of the Trinity, is available as a recording. The celebration of the Feast of the Holy Trinity is attributed to him.
- A. Auda, L'école musicale liégeoise au Xe siècle: Etienne de Liège (Brussels, 1922)
- The Menologies (P.L., CLI, 1020), written during the pontificate of Gregory VII (Nilles, II, 460), call the Sunday after Pentecost a Dominica vacans, with no special Office, but add that in some places they recited the Office of the Holy Trinity composed by Bishop Stephen of Liège (903–20);Catholic Encyclopedia.
Etienne de Liège. In festo sanctissimae trinitatis. Psallentes. RIC 249
- Wilhelm Kohl (1995). "Stephan (von Tongern, Étienne de Liège), Bischof von Lüttich". In Bautz, Traugott. Biographisch-Bibliographisches Kirchenlexikon (BBKL) (in German). 10. Herzberg: Bautz. cols. 1395–1397. ISBN 3-88309-062-X.