HART, P. ’t. J.M. Welcker, Heren en arbeiders in de vroege Nederlandse arbeidersbeweging 1870-1914. BMGN - Low Countries Historical Review, [S. l.], v. 94, n. 2, p. 314–316, 1979. DOI: 10.18352/bmgn-lchr.2107. Disponível em: https://bmgn-lchr.nl/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-102283. Acesso em: 29 mar. 2024.