Hajduk-Stelmachowicz M, Cecuła K, Bełch P, Szczygieł E. The impact of the COVID-19 pandemic on the functioning of selected aero clubs – a preliminary study. Prace KGP PTG [Internet]. 2023 Jun. 29 [cited 2024 May 16];37(2):64–83. Available from: https://prace-kgp.uken.krakow.pl/article/view/9766