Peter Jeffery's Lecture at Axion Estin Foundation held at White Plains
Jeffery, Peter, 2001. The Earliest Oktōēchoi : The Role of Jerusalem and Palestine in the Beginnings of Modal Ordering
. In The study of medieval chant : paths and bridges, East and West ; in honor of Kenneth Levy
. Woodbridge, Suffolk: Boydell Press, pp. 147–209.
Bibliography: Jeffery, Peter, "Oktōēchos", Grove Music Online. Oxford Music Online.
Review: Terzopoulos, Konstantinos, 2001. The Greek Orthodox Theological Review 46, pp. 368-381.