Columbia subject headings:
Air--Pollution--Law and legislation--United States.
Refuse and refuse disposal--Law and legislation--United States.
Water--Pollution--Law and legislation--United States.
Harvard subject headings:
Air--Pollution--Law and legislation--United States
Refuse and refuse disposal--Law and legislation--United States
Water--Pollution--Law and legislation--United States
Princeton subject headings:
Air--Pollution--Law and legislation--United States.
Refuse and refuse disposal--Law and legislation--United States.
Water--Pollution--Law and legislation--United States.