Vernon Bogdanor (November 1995). The Monarchy and the Constitution. Oxford: Clarendon Press. p. 188. ISBN0-19-827769-5. The statement in the book is sourced to "Kenneth Clarke, Chancellor of the Duchy of Lancaster in Hansard, Standing Committee G, col 11, 17 November 1987"
Unger, Paul (5 June 2009). "Duchy courage". Property Week. Archived from the original on 3 September 2014. Retrieved 31 August 2014.{{cite news}}: CS1 maint: bot: original URL status unknown (link)