Columbia subject headings:
Shīʻah--History--Congresses.
Sufism--History--Congresses.
Harvard subject headings:
Islamic sects--Congresses.
Shīʻah--Congresses.
Shīʻah--History--Congresses.
Sufism--Congresses.
Sufism--History--Congresses.
Princeton subject headings:
Islamic sects--Congresses.
Shīʻah--Congresses.
Sufism--Congresses.