Treaties and other international acts series. 2035. Economic cooperation with British/United States Zone, Free Territory of Trieste, under Public law 472, 80th Congress, as amended, agreement between United States and British/United States Zone, Free Territory of Trieste, amending agreement of Oct. 15, 1948, effected by exchange of letters, signed Trieste Dec. 27 and 28, 1949; entered Into force Dec. 28, 1949.