Columbia subject headings:
Hours of labor--United States.
Unemployed--United States.
United States. National Recovery Administration--Codes.
Wages--United States.
Working class--United States.
Harvard subject headings:
Hours of labor--United States
Labor--United States
Unemployed--United States
United States. National Recovery Administration. Codes.
Wages--United States.
Working class--United States
Princeton subject headings:
Hours of labor--United States.
Unemployed--United States.
Wages--United States.
Working class--United States.