Apel, Willi. Gregorian Chant. Bloomington, Indiana.1958.
* Apel, Willi. The Harvard Dictionary of Music. Cambridge. 1944.
Baxter, J. H. and Johnson, Charles. Medieval Latin Word List. London. 1934.
Bukofzer, Manfred. “The Gymel: The Earliest Form of English Polyphony,” in Music and Letters, XVI, No. 2. 1935.
Catholic Encyclopaedia, The. Ed., C. G. Herbermann, E. A. Pace, C. B. Pallen, T. J. Shahan, J. J. Wynne. New York. 1907.
Du Cange, C. du F., sieur. Glossarium mediae et infimae Latinitatis. Paris. 1840-1850.
* Galpin, Francis William, Old English Instruments of Music, their History and Character. London. 1932.
Godefroy, Frédéric Eugène. Dictionnaire de 1!Ancienne Langue Francais. Paris. 1881-1902.
* Grove’s Dictionary of Music and Musicians, 3rd ed. Ed., H. C. Colles. New York. 1938. Ibid. (5th ed.): Ed., Eric Blom. New York. 1955.
Kenney, Silvia W. “English Discant and Discant in England,” in The Musical Quarterly, XLV, No. 1. 1959.
Middle English Dictionary. Ed., Hans Kurath. Ann Arbor, Michigan. 1954-.
Musik in Geschichte und Gegenwart: Allgemeine Enzyklopädie der Musik unter Mitarbeit Zahlreicher Musikforscher der In- und Auslandes, Die. Hrsg., Friederich Blume. Kassel und Basel. 1949.
* Oxford English Dictionary. Ed., James A. H. Murray. Oxford. 1933.
Oxford History of Music. Ed., W. H. Hadow. Oxford. 1901-1905.
Reese, Gustave. Music in the Middle Ages. New York. 1940.
Reese, Gustave. Music in the Renaissance. New York. 1954.
* Sachs, Curt. The History of Musical Instruments. New York. 1940.
* Souter, Alexander. A Glossary of Later Latin. Oxford. 1949.
* Works cited in the dictionary.