DŁUGOSZ, Zbigniew and RAŹNIAK, Piotr. Population Movement and Changes in Population in European Countries - Present State and Perspectives. Bulletin of Geography. Socio-economic Series. Online. 22 December 2008. No. 10, p. 21–36. [Accessed 22 July 2024]. DOI 10.1515/v10089-008-0010-x.