Stepanov, Tsvetelin. 2020. “The History and Culture of Bulgaria in the 7th–12th Centuries: Between Two Easts and Two Wests”. In Phantom of Muhammad, Shade of Samuel Byzantine Empire in Relation to Members of Other Cultures and Religions (7th–15th c.): No. XXXIX, edited by Zofia A. Brzozowska, Mirosław J. Leszka, Kirił Marinow, and Teresa Wolińska, 163-76. Byzantina Lodziensia. Poland: Lodz University Press. https://doi.org/10.18778/8142-804-0.08.