Columbia subject headings:
Labor contract--United States.
Labor laws and legislation--United States.
Law reports, digests, etc.--United States.
United States. National Industrial Recovery Act of 1933.
Working class--United States.
Harvard subject headings:
Labor and laboring classes--United States.
Labor contract--United States.
Labor laws and legislation--United States
Labor--United States
Law reports, digests, etc.--United States.
United States. National Industrial Recovery Act of 1933.
Working class--United States
Princeton subject headings: