Columbia subject headings:
Harvard subject headings:
Yemen, North--Economic conditions--Congresses.
Yemen, North--Social conditions--Congresses.
Yemen, South--Economic conditions--Congresses.
Yemen, South--Social conditions--Congresses.
Princeton subject headings:
Yemen (People's Democratic Republic)--Economic conditions--Congresses.
Yemen (People's Democratic Republic)--Social conditions--Congresses.
Yemen--Economic conditions--Congresses.
Yemen--Social conditions--Congresses.