著者名,書名,版表示,出版者名,出版年,シリーズ名,番号,ISBN,ISSN,URL
"Stefanova, Tatiana and Stepanov, Tsvetelin",The Bulgars and the steppe empire in the early Middle Ages : the problem of the others,,Brill,2010,"East Central and Eastern Europe in the Middle Ages, 450-1450",,9789004180017,,https://cir.nii.ac.jp/crid/1130000795903318400