R. Pütz, Duel in de wolken. De luchtoorlog in de gevarendriehoek Roermond–Luik–Aken. BMGN - Low Countries Historical Review, [S. l.], v. 111, n. 2, p. 284–285, 1996. DOI: 10.18352/bmgn-lchr.4271. Disponível em: https://ojstest.minions.amsterdam/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-104907.. Acesso em: 25 nov. 2024.