DIEPEN, Remco van. D. Engelen, Frontdienst. De BVD in de Koude Oorlog. BMGN - Low Countries Historical Review, [S. l.], v. 124, n. 1, p. 152–153, 2009. DOI: 10.18352/bmgn-lchr.6930. Disponível em: https://bmgn-lchr.nl/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-107974.. Acesso em: 15 oct. 2024.