Columbia subject headings:
Harvard subject headings:
Africa, Central--Emigration and immigration--Economic aspects.
Africa, West--Emigration and immigration--Economic aspects.
Economic development--Africa, Central.
Economic development--Africa, West.
Princeton subject headings:
Africa--Emigration and immigration--Economic aspects--Congresses.
Africa--Emigration and immigration--Social aspects--Congresses.
Economic development--Africa--Congresses.