Darke 1991, p. 141. Darke, Jo (1991). The Monument Guide to England and Wales: A National Portrait in Bronze and Stone. London: MacDonald and Co. OCLC1008240876.
Clark 1980, Introduction. — (1980). The Story of Monmouthshire, Volume 1, From the earliest times to the Civil War. Monmouth: Monnow Press. ISBN978-0-95066-1810. OCLC866777550.