D. Tłoczyński, M. Mosionek-Schweda, A. . Zamojska, and K. . Diakowska, “Impact of COVID-19 state aid funds on the performance of airports in Poland”, EiS, vol. 94, no. 3, p. 1218, Dec. 2025, doi: 10.34659/eis.2025.94.3.1218.