Columbia subject headings:
Land use, Urban--Pennsylvania--Philadelphia.
Philadelphia (Pa.)--Social conditions.
Philadelphia Metropolitan Area (Pa.)--Social conditions.
Harvard subject headings:
Land use, Urban--Pennsylvania--Philadelphia.
Philadelphia (Pa.)--Social conditions.
Philadelphia Metropolitan Area (Pa.)--Social conditions.
Princeton subject headings:
Land use, Urban--Pennsylvania--Philadelphia.
Philadelphia (Pa.)--Social conditions.
Philadelphia metropolitan area (Pa.)--Social conditions.