1. Greenberg, O.W., Mohapatra, R.N.: Phys. Rev. Lett.59, 2507 (1987)
2. Govorkov, A.B.: Sov. J. Part. Nucl.14, 520 (1983)
3. Ohnuki, Y., Kamefuchi, S.: Quantum field theory and parastatistics. Tokyo: University of Tokyo Press 1982
4. Clayton, D.D.: Principles of stellar evolution and nucleosynthesis, pp. 283?435. Chicago: University of Chicago Press 1983
5. Kirsten, T.: In: Proceedings of the Ninth Workshop on Grand Unification, Aix-Les-Bains 1988. Barloutand, R. (ed.). Singapore: World Scientific 1989