Columbia subject headings:
Industrial relations--History--Case studies.
Labor unions--History--Case studies.
Working class--History--20th century--Case studies.
Harvard subject headings:
Industrial relations--History
Industrial relations--History--Case studies.
Labor unions--History
Labor unions--History--Case studies.
Working class--History
Working class--History--20th century--Case studies.
Princeton subject headings:
Industrial relations--History--Case studies.
Labor unions--History--Case studies.
Working class--History--20th century--Case studies.