Kingdoms in Early Anglo-Saxon England. (London: Seaby, 1990. ISBN 1-85264-027-8), pp. 148–158 & p. 133, table 15. Stenton, Frank, Anglo-Saxon England 3rd,
Landscape of Anglo-Saxon England. Leicester University Press. 1998: 46. Yorke, Barbara. Kings and Kingdoms of Early Anglo-Saxon England. London and new York:
[2014-05-27]. (原始内容存档于2014-05-05). Stenton Anglo-Saxon England pp. 105–106 Blair An Introduction to Anglo-Saxon England pp. 116–117 Brooks Early History
pp. 321–322. Stenton, Anglo-Saxon England, p. 328. Yorke, Barbara. Kings and Kingdoms of Early Anglo-Saxon England. London and New York: Routledge. 2002