Columbia subject headings:
Social classes--Soviet Union.
Social classes--United States.
Soviet Union--Social conditions--1970-1991.
United States--Social conditions--1980-2020.
Harvard subject headings:
Social classes--Soviet Union
Social classes--United States
Soviet Union--Social conditions--1970-1991
United States--Social conditions--1980-2020
Princeton subject headings:
Soviet Union--Description and travel.
United States--Description and travel.