Litwińska, Elżbieta. “The Demographic Aspect of Contemporary Urban Processes (The Case of Portugal)”. Bulletin of Geography. Socio-economic Series, no. 15 (May 19, 2011): 71–82. Accessed April 19, 2024. https://apcz.umk.pl/BGSS/article/view/v10089-011-0005-x.