Arnold, Udo. “Ordines Militares ‒ 20 Konferenzen. Der Weg Einer Freundschaft / Ordines Militares – 20 Conferences. The Way of a Friendship”. Ordines Militares Colloquia Torunensia Historica. Yearbook for the Study of the Military Orders 25 (December 29, 2020): 387–420. Accessed April 26, 2024. https://apcz.umk.pl/OM/article/view/OM.2020.015.