Hoszman, Adam, Elżbieta Marciszewska, and Michał Pasztaleniec. “State Aid for Airlines in the EU: Policy Changes During the COVID-19 Pandemic”. Journal of Management and Financial Sciences, no. 46 (March 15, 2023): 77–88. Accessed May 5, 2024. https://econjournals.sgh.waw.pl/JMFS/article/view/3197.