BURGTORF, Jochen. In memoriam: Rudolf Hiestand (1933‒2023). Ordines Militares Colloquia Torunensia Historica. Yearbook for the Study of the Military Orders. Online. 30 December 2023. Vol. 28, pp. 269-278. [Accessed 4 July 2025]. DOI 10.12775/OM.2023.009.