Columbia subject headings:
Mahdī, Muḥammad ibn al-Ḥasan, b. 869
Shīʻah--Customs and practices.
Harvard subject headings:
Mahdī, Muḥammad ibn al-Ḥasan, 869-
Shīʻah--Customs and practices.
Princeton subject headings:
Mahdī, Muḥammad ibn al-Ḥasan, 869-
Shīʻah--Customs and practices.