Czaja, Roman. “ Dirk Schumann (Studien Zur Brandenburgischen Und Vergleichenden . ”. Ordines Militares Colloquia Torunensia Historica. Yearbook for the Study of the Military Orders 21 (May 9, 2017): 233–236. Accessed March 29, 2024. https://apcz.umk.pl/OM/article/view/OM.2016.013.