Columbia subject headings:
Communism--United States--History--20th century.
Communist Party of the United States of America--History--20th century.
Harvard subject headings:
Communism--United States--History--20th century
Communist Party of the United States of America--History--20th century.
Princeton subject headings:
Communism--United States--History--20th century.
Communist Party of the United States of America--History--20th century.