Columbia subject headings:
Harvard subject headings:
Digital mapping--Databases.
Housing--United States--Statistics--Databases.
United States--Census, 2000--Databases.
United States--Population--Statistics--Databases.
Princeton subject headings:
Databases.
Statistics.
United States--Census, 21st, 1990--Databases.
United States--Census, 22nd, 2000--Databases.
United States--Population--Statistics--Databases.