Kuśnierz, R. “Jan Karszo-Siedlewski’s Activity for the Catholic Church in 1935–37: Based on Materials from Surveillance of His Person by Soviet Counterintelligence”. Dzieje Najnowsze, vol. 54, no. 2, Aug. 2022, pp. 49-62, doi:10.12775/DN.2022.2.03.