KWIATKOWSKI, Krzysztof. Radosław Biskup, Das Domkapitel von Samland (1285–1525). Ordines Militares Colloquia Torunensia Historica. Yearbook for the Study of the Military Orders. Online. 1 July 2011. Vol. 16, p. 325. [Accessed 6 July 2025]. DOI 10.12775/NO_DOI_2011_01.