M.W. Grauwen, Norbertus aartsbisschop van Maagdenburg (1126-1134). BMGN - Low Countries Historical Review, [S. l.], v. 95, n. 3, p. 535–538, 1980. DOI: 10.18352/bmgn-lchr.2185. Disponível em: https://ojstest.minions.amsterdam/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-102361.. Acesso em: 21 dec. 2024.