Columbia subject headings:
Harvard subject headings:
Yemen (Republic)--Politics and government--20th century.
Yemen, North--Foreign relations--Yemen, South.
Yemen, South--Foreign relations--Yemen, North.
Yemen, South--Politics and government--20th century.
Princeton subject headings:
Yemen (Republic)--Politics and government--20th century.
Yemen, North--Foreign relations--Yemen, South.
Yemen, South--Foreign relations--Yemen, North.
Yemen, South--Politics and government--20th century.