Columbia subject headings:
Africa--Economic conditions.
Africa--Politics and government--1960-
Africa--Social conditions.
Nigeria--Economic conditions.
Nigeria--Politics and government--1960-
Nigeria--Social conditions.
Harvard subject headings:
Africa--Economic conditions.
Africa--Politics and government--1960-
Africa--Social conditions.
Nigeria--Economic conditions.
Nigeria--Politics and government--1960-
Nigeria--Social conditions.
Princeton subject headings: