Columbia subject headings:
Environmental policy--Congresses.
Environmental policy--Social aspects--Congresses.
Human beings--Effect of environment on--Congresses.
Nature--Effect of human beings on--Congresses.
Harvard subject headings:
Environmental policy--Congresses
Environmental policy--Social aspects--Congresses.
Human beings--Effect of environment on--Congresses.
Nature--Effect of human beings on--Congresses.
Princeton subject headings: