Columbia subject headings:
Inland water transportation--Law and legislation--United States.
Inland water transportation--United States--Transit charges.
User charges--Law and legislation--United States.
Harvard subject headings:
Inland water transportation--Law and legislation--United States
Inland water transportation--United States--Transit charges.
User charges--Law and legislation--United States.
Princeton subject headings:
Inland water transportation--Law and legislation--United States.
Inland water transportation--United States--Transit charges.
User charges--Law and legislation--United States.