WERFF, Y. van der. P.J. Molenaar, De luchtverdediging in de meidagen 1940. BMGN - Low Countries Historical Review, [S. l.], v. 87, n. 2, p. 262–265, 1972. DOI: 10.18352/bmgn-lchr.1728. Disponível em: https://bmgn-lchr.nl/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-101888. Acesso em: 23 apr. 2024.