https://www.geni.com/people/Hrollaug-Eyjafj%C3%B6r%C3%B0ur-%C3%8Dslands/6000000001065449177 

https://www.geni.com/people/Ragnvald-Eysteinsson-Earl-of-M%C3%B8re/6000000001045491041 

http://www.thehennesseefamily.com/getperson.php?personID=I53958&tree=hennessee 

https://www.geni.com/people/Hrolf-Bigod/6000000009437210537 

https://www.geni.com/people/Thurstan-le-Goz-viscount-of-Avranches/6000000002043201155 

https://www.geni.com/people/Hrolf-Bigod/6000000009437210537 

http://www.thehennesseefamily.com/getperson.php?personID=I53956&tree=hennessee