|SOME NOTES ON MEDIEVAL ENGLISH GENEALOGY|
Volume 5, page 344:
He [Sir William de Ferrers (d. 1324/5)] m. Ellen, who is said to have been da. of Sir John DE SEGRAVE, of Chacombe, Northants [LORD SEGRAVE], by Christine, da. of Sir Hugh DE PLESSY, of Hooknorton and Kidlington, Oxon.
Douglas Richardson, in April 2002, posted evidence that tends to support this marriage [citing M.D. Legge, Anglo-Norman Letters and Petitions, pp. 78, 79 (1941)].