Columbia subject headings:
Gréber, Jacques--Congresses.
Landscape architects--France--Congresses.
Landscape architecture--Pennsylvania--Philadelphia--Congresses.
Landscape architecture--United States--Congresses.
Harvard subject headings:
Gréber, Jacques.
Landscape architects--France.
Landscape architecture--Pennsylvania--Philadelphia.
Landscape architecture--United States
Princeton subject headings:
Gréber, Jacques--Congresses.
Landscape architects--France--Congresses.
Landscape architecture--Pennsylvania--Philadelphia--Congresses.
Landscape architecture--United States--Congresses.