Bibliography
Muhammad ibn Jarir al-Tabari History v. 32 "The Reunification of the Abbasid Caliphate", transl. C.E. Bosworth, SUNY, Albany, 1987; v. 33 "Storm and Stress along the Northern Frontiers of the Abbasid Caliphate", transl. C.E. Bosworth, SUNY, Albany, 1991
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