POLEK, K. Frisians of the Early Middle Ages, red. J. Hines, N. Ijssennagger-van der Pluijm, Studies in Historical Archaeoethnology, 10. Kwartalnik Historii Kultury Materialnej, [S. l.], v. 71, n. 1, p. 91–96, 2023. Disponível em: https://journals.iaepan.pl/khkm/article/view/3289. Acesso em: 5 maj. 2024.