Gwynfor Evans, Land of My Fathers: 2000 Years of Welsh History (Y Lolfa, 1974) page 101.
Rice Rees, An Essay on the Welsh Saints Or the Primitive Christians, Usually Considered to Have Been the Founders of the Churches in Wales (Google eBook) (Longman, Rees, Orme, Brown, Green, and Longman, 1836) page 239.
