J.G. Kruisheer, De oorkonden en de kanselarij van de graven van Holland tot 1299. BMGN - Low Countries Historical Review, [S. l.], v. 89, n. 1, p. 126–127, 1974. DOI: 10.18352/bmgn-lchr.1805. Disponível em: https://ojstest.minions.amsterdam/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-101965.. Acesso em: 15 nov. 2024.