Columbia subject headings:
Earthworks (Art)--Congresses.
Landscape architecture--Congresses.
Landscape design--Congresses.
Harvard subject headings:
Earthworks (Art)--Congresses.
Landscape architecture--Congresses
Landscape design--Congresses.
Princeton subject headings:
Earthworks (Art)--Congresses.
Landscape architecture--Congresses.
Landscape design--Congresses.