Welch, Robert, & Bruce Stewart, The Oxford Companion to Irish Literature (Oxford University Press, 1996, ISBN 978-0198661580), p. 359 at google.co.uk
Follett, Westley, Céli Dé in Ireland: Monastic Writing and Identity in the Early Middle Ages (London: Boydell Press, 2006, ISBN 978-1843832768) pp 129–130 at books.google.co.uk