Columbia subject headings:
Asceticism--Islam--Early works to 1800.
Sufism--Doctrines--Early works to 1800.
Harvard subject headings:
Sufism--Doctrines--Early works to 1800
Sufism--Morocco--Early works to 1800.
Princeton subject headings:
Sufism--Doctrines--Early works to 1800.
Sufism--Morocco--Early works to 1800.