Columbia subject headings:
Africa, Sub-Saharan--Economic conditions--1918-1960.
Harvard subject headings:
Africa, Sub-Saharan--Economic conditions--1918-
Africa, Sub-Saharan--Economic conditions--1918-1960.
Princeton subject headings:
Africa, Sub-Saharan--Economic conditions--1918-1960.
Africa, Sub-Saharan--Economic conditions--1960-