ENGELEN, D. F. Hoekstra, In dienst van de BVD. Spionage en contraspionage in Nederland. BMGN - Low Countries Historical Review, [S. l.], v. 120, n. 4, p. 698–699, 2005. DOI: 10.18352/bmgn-lchr.6333. Disponível em: https://bmgn-lchr.nl/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-107258. Acesso em: 2 may. 2024.