JANIEC, Jerzy. Hermann von Wartberge (Warburg) and his Origins. New Research and Outcomes. Studia Europaea Gnesnensia, [S. l.], n. 13, p. 309–322, 2016. Disponível em: https://pressto.amu.edu.pl/index.php/seg/article/view/7355. Acesso em: 22 grudz. 2024.