Siekierska, Anna. “Memoirs of Jan Schwarz (Szwarc) – Pedagogue, Psychologist, Organizer of the State Higher School of Pedagogy in Gdańsk – As a Source for Professional Biography”. Progress, no. 9-10 (December 22, 2021): 273–283. Accessed May 18, 2024. https://czasopisma.bg.ug.edu.pl/index.php/Progress/article/view/6508.