USING   LITERATURE

1. D. Brek: "Zeolite molecular sita", published "MIR", M. 1976
2. G. V. Tsitsishvili, T. G. Andronikashvili. "Natural zeolites and using in national economy", Tbilisi, 1978
3. O. Oniano. Agro-chemistry. published Ganatleba, Tbilisi, 1983
4. Encyclopedia   of school pupil no organic chemistry, published "Sovetskaia Enciklopedia". Moscow, 1975
5. Coordinated science. Consultant editor: Peter Wieding. Cambridge University press.
6. Educational magazine by Soros. 1999
7. A. Orlova. Agro-chemistry laboratory.  1973, "Znai i umei" � children's literature
8. Using klinoptilolit contain tuf in the plants. "Metsniereba", 1988
9. Natural zeolites in agricultural. "Metsniereba", 1997

10.  http://eo.ucar.edu/kids/green/cycles7.htm