Kwiatek, Piotr. “Application of Positive Psychology to Human Formation of Priests and Religious: The Active Program of Positive Personal Development (APPRO)”. Seminare. Learned Investigations 35, no. 3 (December 27, 2022): 99–113. Accessed May 18, 2024. https://czasopisma.uksw.edu.pl/index.php/s/article/view/11077.