Jennifer Michael Hecht, Doubt : A History : The Great Doubters and Their Legacy of Innovation from Socrates and Jesus to Thomas Jefferson and Emily Dickinson, Harper San Francisco, (ISBN0-06-009795-7, lire en ligne)
Zarrīn-kūb, ʿAbd-al-Ḥusain, 1922-1999 Verfasser., Two centuries of silence : an account of events and conditions in Iran during the first two hundred years of Islam, from the Arab invasion to the rise of the Tahirid dynasty, , 410 p. (ISBN978-1-56859-260-2 et 1-56859-260-4, OCLC1019993059, lire en ligne)