KRZYMINIEWSKA, G. Olderpreneur – future market challenges. Bulletin of Geography. Socio-economic Series, [S. l.], v. 51, n. 51, p. 75–84, 2021. DOI: 10.1515/31923. Disponível em: https://apcz.umk.pl/BGSS/article/view/31923. Acesso em: 4 dec. 2021.