St. Lawrence Seaway tariff of tolls : agreements between the United States of America and Canada, amending and supplementing the agreement of March 9, 1959, as amended, and supplemented, effected by exchange of notes, signed at Washington May 7 and December 22, 1987.
Washington, D.C. : Dept. of State : For sale by the Supt. of Docs., U.S. G.P.O., [1993?]