Columbia subject headings:
Water--Pollution--Law and legislation--Wisconsin.
Water--Pollution--United States.
Water--Pollution--Wisconsin.
Harvard subject headings:
Water--Pollution--Law and legislation--Wisconsin.
Water--Pollution--United States
Water--Pollution--Wisconsin.
Princeton subject headings:
Water--Pollution--Law and legislation--Wisconsin.
Water--Pollution--United States.
Water--Pollution--Wisconsin.