Szymańska, Daniela, Elżbieta Grzelak-Kostulska, and Beata Hołowiecka. “Polish Towns and the Changes in Their Areas and Population Densities”. Bulletin of Geography. Socio-economic Series, no. 11 (October 6, 2009): 15–29. Accessed January 18, 2022. https://apcz.umk.pl/BGSS/article/view/v10089-008-0018-2.