Ebels-Hoving, B. “Meer Inzicht in Middeleeuwse Tweedracht?”. BMGN - Low Countries Historical Review 99, no. 2 (January 1, 1984): 219–228. Accessed December 22, 2024. https://bmgn-lchr.nl/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-102684.