Columbia subject headings:
Africa, Sub-Saharan--Antiquities.
Iron age--Africa, Sub-Saharan.
Iron-works--Africa, Sub-Saharan.
Harvard subject headings:
Africa, Sub-Saharan--Antiquities.
Iron age--Africa, Sub-Saharan.
Iron-works--Africa, Sub-Saharan.
Princeton subject headings:
Africa--Antiquities.
Africa--Social life and customs.
Iron age--Africa.
Iron-works--Africa--History.