Columbia subject headings:
Harvard subject headings:
Ibadites--Oman--History--Congresses.
Islam--Oman--History--Congresses.
Islamic sects--Oman--History--Congresses.
Oman--History--Congresses.
Princeton subject headings:
Ibadites--Oman--History--Congresses.
Islam--Oman--History--Congresses.
Islamic sects--Oman--History--Congresses.
Oman--History--Congresses.