1. Frauenfelder H. and Steffen R. M. In: Siegbahn K. (eds), Alpha-, Beta-, and Gamma-ray Spectroscopy, Vol. 2, North Holland, Amsterdan, 1965, p. 995.
2. Schatz G. and Weidinger A., Nuclear Condensed Matter Physics, John Wiley and Sons, New York, 1996.
3. Catchen L., J. Mater. Educ. 12 (1990), 253.
4. Vianden R., Hyperfine Interact. 16 (1983), 1081.
5. Rots M., van Cauteren J., de Doncker G. and Rao G. N., Hyperfine Interact. 35 (1987), 967.