OLECH, Barbara. Selected Aspects of Józef Wittlin’s Franciscanism. Rocznik Teologii Katolickiej, [S. l.], v. 18, p. 101–112, 2019. DOI: 10.15290/rtk.2019.18.07. Disponível em: https://rtk.uwb.edu.pl/index.php/rtk/article/view/111. Acesso em: 4 dec. 2025.