Title: Dawr Banī Sahl al-siyāsī fī khilāfatay al-Amīn wa-al-Maʼmūn /
Authors: Ṭarāwah, Ḥijāzī Ḥasan ʻAlī.
Publisher: Maktabat Zahrāʼ al-Sharq,
Year: 2007
Subjects: Islamic Empire History