Columbia subject headings:
Abbasids.
Islamic Empire--History--750-1258.
Khurāsān (Iran)--History.
Harvard subject headings:
Abbasids.
Islamic Empire--History--750-1258.
Khurāsān (Iran)--History.
Princeton subject headings:
Abbasids.
Islamic Empire--History--661-750.
Islamic Empire--History--750-1258.
Khurāsān (Iran)--Biography.
Khurāsān (Iran)--History.