From John Esposito, Unholy War: Terror in the Name of Islam (Oxford, 2002), pp. 43–46; David Cook, Understanding Jihad (Berkeley, Los Angeles and London, 2005), pp. 63–66; Bonner, Jihad in Islamic History, pp. 143–44; Marshall G. S. Hodgson, The Venture of Islam: Conscience and History in a World Civilisation (Chicago and London, 1974), pp. 468–71; Natana J. Delong-Bas, Wahhabi Islam: From Revival and Reform to Global Jihad (Cairo, 2005), pp. 247–55; Hillenbrand, Crusades, pp. 241–43