Columbia subject headings:
Harvard subject headings:
China--Social policy.
Communism--China
Communism--Soviet Union
Labor--China
Labor--Soviet Union
Soviet Union--Social policy.
Working class--China
Working class--Soviet Union
Princeton subject headings:
China--Social policy.
Communism--China.
Communism--Soviet Union.
Soviet Union--Social policy.
Working class--China.
Working class--Soviet Union.