Krylasova, N.B., et al. “MAIN RESULTS OF THE PROJECT ‘MEDIEVAL PERM CIS-URALS: CHANGING POPULATION IN A CHANGEABLE ENVIRONMENT’”. Perm Federal Research Centre Journal, no. 4, Dec. 2016, pp. 33-37, https://journal.permsc.ru/index.php/pscj/article/view/PSCJ2016n4p6.