KRUL, W.E. J.F. Heijbroek, E.L. Wouthuysen, Kunst, kennis en commercie. De kunsthandelaar J. H. de Bois 1878-1946. BMGN - Low Countries Historical Review, [S. l.], v. 109, n. 3, p. 494–495, 1994. DOI: 10.18352/bmgn-lchr.3903. Disponível em: https://bmgn-lchr.nl/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-104485.. Acesso em: 21 nov. 2024.