Mark Cohen, "Geniza Documents Concerning a Conflict in a Provincial Egyptian Jewish Community during the Nagidate of Mevorakh B. Saadya," in Studies in Judaism and Islam Presented to Shelomo Dov Goitein on the Occasion of his Eightieth Birthday (Jerusalem: Magnes Press, Hebrew University, 1981), 123-54.
Mark Cohen, Jewish Self-Government in Medieval Egypt: The Origins of the Office of the Head of the Jews, ca. 1065-1126 (Princeton, New Jersey: Princeton University Press, 2014).