Galkina, Elena. Оn the role of the Great Bulgaria in the ethnopolitical history of Eastern Europe Written by Сосницкий Дмитрий Александрович on 20 June 2014.
Polyvyannyj, D. I. Bulgars and Slavs and «friends» of among enemies the Byzantine Empire in the 7th–9th cc. Written by Сосницкий Дмитрий Александрович on 31 December 2016.
Stepanov, Tsvetelin Yordanov, State-formation in Danubian Bulgaria, AD 681–865: Religious dimensions Written by Сосницкий Дмитрий Александрович on 02 December 2013.
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