The caliphs and their non-Muslim subjects : a critical study of the Covenant of 'Umar, 2026-02-15T16:32:59+03:00 DEBUG: VuFind\ILS\Driver\Folio: Token taken from global cache: eyJhbGciOiJIUzI1NiJ9.eyJzdWIiO... - Tritton, A. S. (Arthur Stanley), 1881 (Islam and the Muslim world, 1970)