International Atomic Energy Agency, Vienna (Austria); Proceedings series; 623 p; ISBN 92-0-103293-5; ; 1993; p. 551-554; IAEA; Vienna (Austria); International symposium on applications of isotope techniques in studying past and current environmental changes in the hydrosphere and the atmosphere; Vienna (Austria); 19-23 Apr 1993; IAEA-SM--329/51P; ISSN 0074-1884;