Music from the Earliest Notations to the Sixteenth Century

2 Eudes de Sully, Contra facientes festum fatuorum, in Jacques Paul Migne, ed., Patrologiae cursus completus, Series Latina, CCXII
(Paris, 1853), col. 70ff. See Janet Knapp, “Polyphony at Notre Dame of Paris,” in R. Crocker and D. Hiley, eds., The New Oxford
History of Music, Vol. II (2nd ed., Oxford and New York: Oxford University Press, 1990), pp. 561–62.