“I.J. Blanken, De Ontwikkeling Van De N.V. Philips’ Gloeilampenfabrieken Tot Elektrotechnisch Concern 1922-1934”. BMGN - Low Countries Historical Review 109, no. 4 (January 1, 1994): 687–688. Accessed November 16, 2024. https://ojstest.minions.amsterdam/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-104531.