Columbia subject headings:
Land use--Planning--Law and legislation--Switzerland--Congresses.
Regional planning--Law and legislation--Switzerland--Congresses.
Zoning law--Switzerland--Congresses.
Harvard subject headings:
Environmental law--Switzerland--Congresses.
Federal government--Switzerland--Congresses.
Land use--Law and legislation--Switzerland--Congresses.
Regional planning--Law and legislation--Switzerland--Congresses.
Princeton subject headings: