H.J. Langeveld, Protestants en progressief. De Christelijk-Democratiesche Unie 1926-1946. BMGN - Low Countries Historical Review, [S. l.], v. 108, n. 3, p. 530–532, 1993. DOI: 10.18352/bmgn-lchr.3760. Disponível em: https://ojstest.minions.amsterdam/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-104313.. Acesso em: 23 nov. 2024.