New York: Columbia University.CS1 maint: ref=harv (link) Bates, Michael L. (7 August 2019), Names and Titles on Islamic Coins, retrieved 23 February 2020CS1 maint: ref=harv (link) Bedrosian, Robert (2006), Ghewond's History, Translated from Classical Armenian, retrieved 23 February 2020CS1 maint: ref=harv (link) Bonner, Michael (Jan–Mar 1988). "Al-Khalīfa Al-Marḍī: The Accession of Hārūn Al-Rashīd". Journal of the American Oriental Society.