Northedge 2006. Northedge, Alastair (2006). "SAMARRA". In Meri, Josef W. (ed.). Medieval Islamic Civilization An Encyclopedia. Vol. 1. Routledge. pp. 694–697. ISBN9780415966924.
Hulmes 2008. Hulmes, Edward D. A. (2008). "'ALI AL-HADI". In Netton, Ian Richard (ed.). Encyclopedia of Islamic Civilisation and Religion. Routledge. p. 43. ISBN9780700715886.
Daftary & Nanji 2014, p. 644. Daftary, Farhad; Nanji, Azim (2014). "Twelver Shi'ism". In Fitzpatrick, Coeli; Walker, Adam Hani (eds.). Muhammad in History, Thought, and Culture: An Encyclopedia of the Prophet of God. Vol. 2. ABC-CLIO. pp. 644–651. ISBN9781610691772.