Philippus Breuker, Het landschap van de Friese klei: 800-1800. BMGN - Low Countries Historical Review, [S. l.], v. 133, 2018. DOI: 10.18352/bmgn-lchr.10541. Disponível em: https://ojstest.minions.amsterdam/article/view/6782.. Acesso em: 22 nov. 2024.