Columbia subject headings:
Government publications--United States--Bibliography.
Labor--Bibliography.
United States. Bureau of Labor Statistics--Bibliography.
Harvard subject headings:
Government publications--United States--Bibliography.
Labor--Bibliography
United States. Bureau of Labor Statistics--Bibliography.
Working class--Bibliography.
Princeton subject headings:
Bibliographies.
Government publications--United States--Bibliography.
Labor--United States--Bibliography.
United States. Bureau of Labor Statistics--Bibliography.