Columbia subject headings:
Harvard subject headings:
Communism--United States--1917-
Foster, William Z., 1881-1961.
Labor unions--United States
Working class--United States
Working class--United States--Biography
Princeton subject headings:
Communism--United States.
Foster, William Z., 1881-1961.
Labor unions--United States.
Working class--United States--Biography.
Working class--United States.