Columbia subject headings:
Nigeria--Economic conditions--1960-
Nigeria--Economic conditions--To 1960.
Nigeria--Economic policy.
Petroleum industry and trade--Nigeria.
Harvard subject headings:
Nigeria--Economic conditions--1960-
Nigeria--Economic conditions--To 1960.
Nigeria--Economic policy.
Petroleum industry and trade--Nigeria
Princeton subject headings:
Nigeria--Economic conditions--1960-
Nigeria--Economic conditions--To 1960.
Nigeria--Economic policy.
Petroleum industry and trade--Nigeria.