SOJKA, E. Process of Ageing of Śląskie Voivodship Population Until 2035. Bulletin of Geography. Socio-economic Series, [S. l.], n. 16, p. 121–138, 2011. DOI: 10.1515/v10089-011-0018-5. Disponível em: https://apcz.umk.pl/BGSS/article/view/v10089-011-0018-5. Acesso em: 6 dec. 2021.