Columbia subject headings:
Ibadites--Africa, North--History.
Ibadites--History--Congresses.
Islam--Doctrines--Congresses.
Harvard subject headings:
Ibadites--Historiography--Congresses.
Ibadites--History--Sources--Congresses.
Ibadites--Oman--History--Sources--Congresses.
Princeton subject headings:
Ibadites--Africa, North--History.
Ibadites--History--Congresses.
Islam--Doctrines--Congresses.