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2. R. T. Liddicoat,Handbook of Gem Identification (Gemological Institute of America, Los Angeles, 1969).
3. R. C. Weast,Handbook of Physics and Chemistry (The Chemical Rubber Co., Cleveland, 1970).
4. S. S. Nargolwalla and E. P. Przybylowicz,Activation Analysis with Neutron Generators (John Wiley & Sons, New York, 1973).
5. G. Crdtmann,Neutron Activation Tables (Springer-Verlag, New York, 1976).