H. Goedkoop, Geluk. Het leven van Herman Heijermans. BMGN - Low Countries Historical Review, [S. l.], v. 112, n. 2, p. 289–290, 1997. DOI: 10.18352/bmgn-lchr.4488. Disponível em: https://ojstest.minions.amsterdam/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-105174.. Acesso em: 2 jul. 2024.