Kuzminykh, S. V., and I. V. Belozyorova. “A.S. BASHKIROV AND ARCHAEOLOGY of VOLGA BULGARIA”. Arkheologiia Evraziiskikh Stepei (Archaeology of the Eurasian Steppes), no. 1, July 2017, pp. 196-18, https://evrazstep.ru/index.php/aes/article/view/146.