Van den Gheyn, Joseph, Catalogue des manuscrits de la Bibliothèque Royale de Belgique vol. 5: Histoire — hagiographie, Brussels, Lambertin (1905), 384–389.
Gratton-Flood, W.H. (1 March 1907). "The Twelve Apostles of Erin". The Catholic Encyclopedia. I. New York: Robert Appleton Company. Retrieved 9 February 2008.