Walker, Timea (2 February 2022). "Sidney Sussex College". www.undergraduate.study.cam.ac.uk. Retrieved 2 November 2022.
historymagpie.com
Montague-Smith, P.W. (ed.), Debrett's Peerage, Baronetage, Knightage and Companionage, Kelly's Directories Ltd, Kingston-upon-Thames, 1968, p. 336, Viscount de L'Isle; for a history of this crest, said to have been copied from the heraldic emblem of King Louis XII by Sir William Sidney, see [1]