Columbia subject headings:
Communism--Yemen (Republic)
Yemen (Republic)--Politics and government--20th century.
Harvard subject headings:
Communism--Yemen (Republic)
Yemen (Republic)--Politics and government--20th century.
Princeton subject headings:
Communism--Yemen (Republic).
Yemen (Republic)--Politics and government--20th century.
Zayd, Sulṭān Aḥmad.