Columbia subject headings:
Canadian Labour Congress--History.
Congress of Industrial Organizations (U.S.)--History.
Labor unions--Canada--History.
Harvard subject headings:
Canadian Labour Congress--History.
Congress of Industrial Organizations (U.S.)--History.
Labor unions--Canada--History
Princeton subject headings:
AFL-CIO--History.
Congress of Industrial Organizations (U.S.)--History.
Labor unions--Canada--History.