Kwaśny J, Mroczek A, Ulbrych M. Externalities of knowledge diffusion in cities and the COVID-19 pandemic. Prace KGP PTG [Internet]. 2022 Jun. 29 [cited 2024 Nov. 21];36(2):231–243. Available from: https://prace-kgp.uken.krakow.pl/article/view/8991