R.M. van Heeringen, P.A. Henderikx, A. Mars, Vroeg-middeleeuwse ringwalburgen in Zeeland. BMGN - Low Countries Historical Review, [S. l.], v. 112, n. 4, p. 536–538, 1997. DOI: 10.18352/bmgn-lchr.4577. Disponível em: https://ojstest.minions.amsterdam/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-105273.. Acesso em: 2 jul. 2024.