Frijhoff, W.Th.M. “J. Koopmans, Rhetoric - Rhétoriqueurs - Rederijkers. Proceedings of the Colloquium, Amsterdam, 10-13 November 1993”. BMGN - Low Countries Historical Review 112, no. 2 (January 1, 1997): 265–266. Accessed April 27, 2024. https://bmgn-lchr.nl/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-105156.