Columbia subject headings:
Harvard subject headings:
Gardens--Design--Congresses.
Gardens--Europe--History--19th century--Congresses.
Landscape gardening--Europe--History--19th century--Congresses.
Urban landscape architecture--Europe--History--19th century--Congresses.
Urban parks--Europe--History--19th century--Congresses.
Princeton subject headings:
Gardens--Europe--Congresses.
Parks--Europe--Congresses.