Columbia subject headings:
Environmental law--Europe--Congresses.
Environmental law--European Economic Community countries--Congresses.
Environmental law--United States--Congresses.
Harvard subject headings:
Environmental law--Europe--Congresses.
Environmental law--European Economic Community countries--Congresses
Environmental law--United States--Congresses
Princeton subject headings:
Environmental law--Europe--Congresses.
Environmental law--European Economic Community countries--Congresses.
Environmental law--United States--Congresses.