PTAK, Mariusz. Lake Evolution in the Żnin Region in the Years 1912– 1960 (Central Poland). Quaestiones Geographicae, [S. l.], v. 32, n. 1, p. 21–26, 2013. DOI: 10.2478/quageo-2013-0003. Disponível em: https://pressto.amu.edu.pl/index.php/qg/article/view/quageo-2013-0003. Acesso em: 17 jul. 2024.