Columbia subject headings:
Geology, Economic--Africa--Periodicals.
Mineral industries--Africa--Periodicals.
Mineral industries--Periodicals.
Periodicals.
Harvard subject headings:
Geology, Economic--Africa--Periodicals.
Mineral industries--Africa--Periodicals.
Mineral industries--Periodicals
Princeton subject headings:
Mines and mineral resources--Africa--Periodicals.
Mines and mineral resources--Periodicals.
Periodicals.