Columbia subject headings:
Forest canopies--United States--States--Statistics.
Forest canopies--United States.
Land use--United States--States--Statistics.
Metropolitan areas--United States--States--Statistics.
Urban forestry--United States--States--Statistics.
Urban forestry--United States.
Harvard subject headings:
Forest canopies--United States--States--Statistics.
Forest canopies--United States.
Land use--United States--States--Statistics.
Metropolitan areas--United States--States--Statistics.
Urban forestry--United States--States--Statistics.
Urban forestry--United States.
Princeton subject headings: