Arabs, Islam and the Arab caliphate in the early Middle Ages /
Beli︠a︡ev, Evgeniĭ Aleksandrovich.
Gourevitch, Adolphe.
New York Praeger London Pall Mall P
1969
Originally published as 'Araby, islam i arabskii khalifat v rannee srednevekov'e', 2. izd. Moscow: Nauka, 1966