Senate executive documents, 89th Congress, 1st session. G. Supplementary income tax protocol with Belgium, message from President of United States transmitting protocol signed Brussels, May 21, 1965, modifying and supplementing convention of Oct. 28, 1948, between United States and Belgium for avoidance of double taxation and prevention of fiscal evasion with respect to taxes on income, as amended by supplementary conventions of Sept. 9, 1952 and Aug. 22, 1957.