Hajduk-Stelmachowicz, Marzena, Paulina Bełch, Elżbieta Szczygieł, Barbara Fura, and Michał Piotr Frankiewicz. 2025. “Impact of COVID-19 Pandemic on the Air Quality of Polish Cities – Challenges for Managers”. Economics and Environment 90 (3): 784. https://doi.org/10.34659/eis.2024.90.3.784.