Conrad, Lawrence I. (1982). "Taun and Waba: Conceptions of Plague and Pestilence in Early Islam". Journal of the Economic and Social History of the Orient. 25 (3): 268–307 [278]. doi:10.2307/3632188. JSTOR3632188.
El Hamel, Chouki (2002), "'Race', slavery and Islam in Maghribi Mediterranean thought: the question of the Haratin in Morocco", The Journal of North African Studies, 7 (3): 29–52 [39–42], doi:10.1080/13629380208718472
Conrad, Lawrence I. (1982). "Taun and Waba: Conceptions of Plague and Pestilence in Early Islam". Journal of the Economic and Social History of the Orient. 25 (3): 268–307 [278]. doi:10.2307/3632188. JSTOR3632188.