Columbia subject headings:
Human settlements--United States.
Twenty-first century--Forecasts.
United States--Social conditions--1980-2020.
Harvard subject headings:
Human settlements--United States.
Twenty-first century--Forecasts
United States--Social conditions--1980-2020
Princeton subject headings:
Human settlements--United States.
Twenty-first century--Forecasts.
United States--Social conditions--1980-2020.