SOURCE-14226Research NeededProbable
Charles Cawley, "Holland, Frisia, Gelre: Chapter 2. Counts of Holland [900]-1299...
Full citation
Charles Cawley, "Holland, Frisia, Gelre: Chapter 2. Counts of Holland [900]-1299: Floris IV died 1234", Medieval Lands: A prosopography of medieval European noble and royal families, v4.1 Updated 16 November 2017, (http://fmg.ac/Projects/MedLands/HOLLAND.htm#FlorisIVdied1234 : accessed 22 January 2018).