Engelen, Th.L.M. “E.J. Fischer, J.L.J.M. Van Gerwen, H.J.M. Winkelman, Bestemming Semarang. Geschiedenis Van De Textielfabrikanten Gelderman in Oldenzaal 1817-1970”. BMGN - Low Countries Historical Review 108, no. 3 (January 1, 1993): 507–508. Accessed April 26, 2024. https://bmgn-lchr.nl/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-104299.