K. Sipowicz, “Repression of Polish Catholic Clergy in Reichsgau Wartheland 1939-1945”, FetR, vol. 30, no. 2, pp. 279–290, Jun. 2017, Accessed: Oct. 08, 2025. [Online]. Available: https://fidesetratio.com.pl/ojs/index.php/FetR/article/view/693