MOORMAN, E. W. Otterspeer, Bolland. Een biografie. BMGN - Low Countries Historical Review, [S. l.], v. 113, n. 1, p. 124–126, 1998. DOI: 10.18352/bmgn-lchr.4655. Disponível em: https://bmgn-lchr.nl/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-105351. Acesso em: 3 may. 2024.