Domanovska, Marina. “M. S. Drinov on Rus’ and Byzantium As Enemies of Bulgaria in the Tenth Century”. V. N. Karazin Kharkiv National University Bulletin ‘History of Ukraine. Ukrainian Studies: Historical and Philosophical Sciences’ 18, no. 1119 (1). Accessed April 29, 2024. https://periodicals.karazin.ua/uahistory/article/view/1390.