Łuczak, Maciej, and Leonard Nowak. “Professor Jerzy Gaj (1929–2016). Outstanding Historian of Physical Culture”. Sport and Tourism Central European Journal 16, no. 2 (April 3, 2019): 11–26. Accessed April 19, 2024. https://czasopisma.ujd.edu.pl/index.php/sport/article/view/328.