MOL, Johannes Adriaan. Singing nuns and lay sisters in the Frisian houses of the Teutonic Order to 1510. Ordines Militares Colloquia Torunensia Historica. Yearbook for the Study of the Military Orders. Online. 30 December 2024. Vol. 29, pp. 313-335. [Accessed 14 December 2025]. DOI 10.12775/OM.2024.013.