Columbia subject headings:
Harvard subject headings:
Agriculture--Switzerland--History--Congresses.
Human geography--Switzerland--History--Congresses.
Land use--Switzerland--History--Congresses.
Mountain life--Switzerland--History--Congresses.
Princeton subject headings:
Agriculture--Switzerland--History--Congresses.
Human geography--Switzerland--History--Congresses.
Land use--Switzerland--History--Congresses.
Mountain life--Switzerland--History--Congresses.