Stepanov, T., & Stefanova, T. (2010). The Bulgars and the Steppe Empire in the Early Middle Ages: The problem of the others. Brill.
Lua i Stíl Chicago (17ú heag.)Stepanov, T͡Svetelin, agus Tati͡ana Stefanova. The Bulgars and the Steppe Empire in the Early Middle Ages: The Problem of the Others. Leiden [The Netherlands] ; Boston: Brill, 2010.
Lua MLA (9ú heag.)Stepanov, T͡Svetelin, agus Tati͡ana Stefanova. The Bulgars and the Steppe Empire in the Early Middle Ages: The Problem of the Others. Brill, 2010.
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