Nyussupova, Gulnara, and Irina Rodionova. “Demographic Situation and the Level of Human Development of the Republic of Kazakhstan: Regional Aspects”. Bulletin of Geography. Socio-economic Series, no. 16 (December 1, 2011): 75–87. Accessed January 18, 2022. https://apcz.umk.pl/BGSS/article/view/v10089-011-0015-8.