Columbia subject headings:
Nigeria--Politics and government--1984-1993.
Nigeria--Politics and government--1993-2007.
Harvard subject headings:
Nigeria--Politics and government--1984-1993.
Nigeria--Politics and government--1993-
Nigeria--Politics and government--1993-2007.
Princeton subject headings:
Nigeria--Politics and government--1984-1993.
Nigeria--Politics and government--1993-2007.