Manakov, Andrei, and Pavel Suvorkov. “Analysis of Demographic Processes in Poland and the Baltic States since the End of the XVIII Century and Forecast up to 2096”. Journal of Geography, Politics and Society, vol. 7, no. 4, Dec. 2017, pp. 5-13, https://czasopisma.bg.ug.edu.pl/index.php/JGPS/article/view/3562.