1. Charles Edwards,Hanes y Ffydd yng Nghymru(Caerdydd, 1948), p. 32; Theophilus Evans,Drych y Prif Oesoedd(Caerdydd, 1961), p. 211.
2. Samuel Lewis,A Topographical Dictionary of Wales, 3rd edn (1844), p. 67.
3. Venerabilis Baedae Historia Ecclesiastica, ed. Charles Plummer (Oxonii, 1896),ii, 77.
4. Lloyd J.E.A History of Wales(1911), p. 181.
5. Hugh Williams,Christianity in Early Britain(Oxford, 1912), p. 200.