Wolffram, D.J. “J.-J. Van Den Berg, Deining. Koers En Karakter Van De ARP Ter Discussie, 1956-1970”. BMGN - Low Countries Historical Review 115, no. 3 (January 1, 2000): 498–500. Accessed April 19, 2024. https://bmgn-lchr.nl/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-106119.