Koelewijn, H.E. “H. Pijfers, J. Roes, Memoriale. Katholiek Leven in Nederland in De Twintigste Eeuw”. BMGN - Low Countries Historical Review 114, no. 3 (January 1, 1999): 458–459. Accessed May 19, 2024. https://bmgn-lchr.nl/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-105805.