MacDonald, IG (2013). Clerics and Clansmen: The Diocese of Argyll between the Twelfth and Sixteenth Centuries. The Northern World: North Europe and the Baltic c. 400–1700 AD. Peoples, Economics and Cultures (series vol. 61). Leiden: Brill. ISBN978-90-04-18547-0. ISSN1569-1462., p. 37; Woolf, A (2004). "The Age of Sea-Kings, 900–1300". In Omand, D (ed.). The Argyll Book. Edinburgh: Birlinn. pp. 94–109. ISBN1-84158-253-0., p. 102.