Columbia subject headings:
Labor unions--Law and legislation--United States.
Strikes and lockouts--Law and legislation--United States.
Strikes and lockouts--United States.
Violence (Law)--United States.
Harvard subject headings:
Labor laws and legislation--United States
Labor unions--Law and legislation--United States
Strikes and lockouts--Law and legislation--United States
Strikes and lockouts--United States
United States. National Labor Relations Board
Violence (Law)--United States.
Princeton subject headings:
Labor unions--Law and legislation--United States.
Strikes and lockouts--United States.
Violence (Law)--United States.