Welch, Robert; Stewart, Bruce (1996). The Oxford Companion to Irish Literature. Oxford University Press. p. 359. ISBN978-0-19-866158-0.
Follett, Westley (2006). Céli Dé in Ireland: Monastic Writing and Identity in the Early Middle Ages. London: Boydell Press. p. 129–130. ISBN978-1-84383-276-8 – via books.google.co.uk.