Columbia subject headings:
Africa, Northeast--History.
Islam--Africa, Northeast--History--19th century.
Islam--Africa, Northeast--History--20th century.
Harvard subject headings:
Africa, North--History.
Africa, North--Religious life and customs.
Africa, Northeast--History.
Islam--Africa, North--History
Islam--Africa, Northeast--History--19th century.
Islam--Africa, Northeast--History--20th century.
Princeton subject headings:
Islam--Africa, Northeast--History.