Чугуй, Тарас. 2019. “Rus’, Hungary and the Holy Roman Empire in the International Relations of The Second Third of the 13th Century: Actual Problems of Historiography”. V. N. Karazin Kharkiv National University Bulletin ‘History of Ukraine. Ukrainian Studies: Historical and Philosophical Sciences’ 28 (October), 6-18. https://doi.org/10.26565/2227-6505-2019-28-01.