Columbia subject headings:
Income distribution--United States.
Poor--Employment--United States.
United States--Economic conditions--1971-1981.
United States--Economic conditions--1981-2001.
Working class--United States.
Working poor--United States--Economic conditions.
Harvard subject headings:
Income distribution--United States.
Poor--Employment--United States
Poverty--United States
United States--Economic conditions--1945-
Working class--United States
Working poor--United States--Economic conditions--20th century.
Princeton subject headings:
Income distribution--United States.
Poor--Employment--United States.
Poverty--United States.
United States--Economic conditions--1945-
Working class--United States.
Working poor--United States--Economic conditions--20th century.