Columbia subject headings:
Harvard subject headings:
Caliphs in the Hadith
Caliphs--Biography
Imamate--Early works to 1800
Islamic Empire--History--622-661
Islamic Empire--Kings and rulers--Biography.
Shīʻah--Early works to 1800
Princeton subject headings:
Caliphs in the Hadith.
Imamate--Early works to 1800.