Columbia subject headings:
Historic sites--Conservation and restoration--United States--Bibliography.
Landscape architecture--Conservation and restoration--United States--Bibliography.
Landscape protection--United States--Bibliography.
Harvard subject headings:
Historic sites--Conservation and restoration--United States--Bibliography.
Landscape gardening--United States--Bibliography.
Landscape protection--United States--Bibliography.
Princeton subject headings:
Historic sites--Conservation and restoration--United States--Bibliography.
Landscape gardening--United States--Bibliography.
Landscape protection--United States--Bibliography.