Lanigan: Ecclesiastical History of Ireland (Dublin, 1829);
Montalembert: Monks of the West (Edinburgh, 1861); Moran: Irish
Saints in Great Britain (Dublin, 1903); Dalgairns: Apostles of Europe
(London, 1876); Healy: Ireland's Ancient Schools and Scholars
(Dublin, 1890); Barrett: A Calendar of Scottish Saints (Fort
Augustus, 1904); Stokes: Six Months in the Apennines (London, 1892),
Three Months in the Forests of France (London, 1895); Fowler: Vita S.
Columbae (Oxford, 1894); Wattenbach: Articles in Ulster Journal of
Archaeology, vol. 7 (Belfast, 1859); Gougaud: Les Chrétientés
celtiques (Paris, 1911); Hogan: Articles in Irish Ecclesiastical
Record, 1894, 1895; Drane: Christian Schools and Scholars (London,
1881).