Callahan, Victoria Woods. 1976. 'Ut Phoebi radiis': The Riddle of the Text Resolved. Josquin des Prez. Proceedings of the International Josquin Festival-Conference Held at the Julliard School at Lincoln Center in New York City, 21-25 June 1971, edited by Edward E Lowinksy and Bonnie J Blackburn, 560-563. London.