Columbia subject headings:
Nigeria--Politics and government--1960-1975.
Nigeria--Politics and government--1975-1979.
Harvard subject headings:
Nigeria--Politics and government--1960-1975.
Nigeria--Politics and government--1975-
Nigeria--Politics and government--1975-1979.
Nigeria--Politics and government--1979-1983.
Princeton subject headings:
Nigeria--Politics and government--1960-1975.
Nigeria--Politics and government--1975-.