Matarasso, Francois. The English Castle. London: Cassell. 1995: 224. ISBN 1-84067-230-7.
Allen Brown, R; Colvin, H M; Taylor, A J. The history of the King's Works: the Middle Ages 2. London: Her Majesty's Stationery Office. 1963: 571–2. 使用|accessdate=需要含有|url= (帮助)