Columbia subject headings:
Environmental law--United States.
Environmental policy--United States.
Pollution--Law and legislation--United States.
Pollution--United States.
Harvard subject headings:
Environmental law--United States
Environmental policy--United States
Pollution--Law and legislation--United States
Pollution--United States
Princeton subject headings:
Environmental law--United States.
Environmental policy--United States.
Pollution--Law and legislation--United States.
Pollution--United States.