Columbia subject headings:
Collective labor agreements--United States--Congresses.
Labor unions--Law and legislation--United States--Congresses.
Harvard subject headings:
Collective labor agreements--United States--Congresses.
Labor unions--Law and legislation--United States--Congresses.
Labor unions--United States--Congresses
Princeton subject headings:
Collective labor agreements--United States--Congresses.
Labor unions--Law and legislation--United States--Congresses.