Ostasiewicz, Stanisława, and Józef Ledzianowski. “Selected Determinants of Demographic Safety”. Journal of Agribusiness and Rural Development 41, no. 3 (December 31, 2016): 365-372. Accessed May 9, 2024. http://www1.up.poznan.pl/jard/index.php/jard/article/view/201.