- [S3] Medieval Lands: A Prosopography of Medieval European Noble and Royal Families, Cawley, Charles, (http://fmg.ac/Projects/MedLands), England, Earls - creations 1207-1297 [accessed 28 Jun 2006].
- [S20] Magna Carta Ancestry: A study in Colonial and Medieval Families, Richardson, Douglas, (Kimball G. Everingham, editor. 2nd edition, 2011), vol. 4 p. 72.
- [S39] Medieval, royalty, nobility family group sheets (filmed 1996), Church of Jesus Christ of Latter-day Saints. Family History Department. Medieval Family History Unit, (Manuscript. Salt Lake City, Utah : Filmed by the Genealogical Society of Utah, 1996), FHL film 1553977-1553985..