VRIES, B.M.A. de. H. Gras, Geschiedenis van Assen. BMGN - Low Countries Historical Review, [S. l.], v. 117, n. 1, p. 78–80, 2002. DOI: 10.18352/bmgn-lchr.5612. Disponível em: https://bmgn-lchr.nl/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-106444. Acesso em: 15 aug. 2026.