Ocherki vizantiyskoy kulʹtury po dannym grecheskoy agiografii.

by Rudakov, Aleksandr Petrovich, 1886-
London, Variorum Reprints, 1970

Byzantium and the Slavs: collected studies /

by Obolensky, Dimitri, 1918-2001
London : Variorum Reprints, 1971