Columbia subject headings:
Sufi literature--19th century--History and criticism.
Sufis--Books and reading--History--19th century.
Sufism--History--19th century.
Harvard subject headings:
Sufi literature--19th century--History and criticism--Congresses.
Sufis--Books and reading--History--19th century--Congresses.
Sufism--History--19th century--Congresses.
Princeton subject headings:
Sufi literature--19th century--History and criticism.
Sufis--Books and reading--History--19th century.
Sufism--History--19th century.