Muhammad ibn Jarir al-Tabari History v. 25 "The End of Expansion," transl. Khalid Yahya Blankinship, SUNY, Albany, 1989; v. 26 "The Waning of the Umayyad Caliphate," transl. Carole Hillenbrand, SUNY, Albany, 1989; v. 27 "The Abbasid Revolution," transl. John Alden Williams, SUNY, Albany, 1985
Sir John Glubb, The Empire of the Arabs, Hodder and Stoughton, London, 1963