Columbia subject headings:
Communism--History.
Labor unions and communism--History--20th century.
World politics--1933-1945.
Harvard subject headings:
Communism--History--20th century
Labor unions and communism--History--20th century.
World politics--1933-1945
Princeton subject headings:
Communism--History--20th century.
Labor unions and communism--History--20th century.
World politics--1933-1945.