Columbia subject headings:
Communism--France--History--20th century.
Communism--United States--History--20th century.
Communist parties--France--History--20th century.
Communist parties--United States--History--20th century.
Harvard subject headings:
Communism--France--History--20th century
Communism--United States--History--20th century
Communist parties--France--History--20th century.
Communist parties--United States--History--20th century.
Princeton subject headings:
Communism--France--History--20th century.
Communism--United States--History--20th century.
Communist parties--France--History--20th century.
Communist parties--United States--History--20th century.