Organized by the International Atomic Energy Agency and held in Vienna, 7-11 July, 1969. organized by the International Atomic Energy Agency and held in Vienna, 9-13 Dec. 1974. organized by the International Atomic Energy Agency and held in Vienna, 27-31 January 1975. organized by the International Atomic Energy Agency and held in Vienna, 15-19 March 1971. organized by the International Atomic Energy Agency and held in Vienna, 25-29 Nov. 1974. organized by the International Atomic Energy Agency and held in Vienna, 2-6 October 1978. organized by the International Atomic Energy Agency and held in Cannes, 24-28 April 1978. organized by International Atomic Energy Agency and held in Vienna 18-22 January, 1971. organized by International Atomic Energy Agency and held in Vienna 18-22 January, 1978. organized by the International Atomic Energy Agency and held in Berlin (West), 6-10 April 1981.