1. B. Pontecorvo: Sov. Phys. JETP26, 984 (1968); V. Gribov, B. Pontecorvo: Phys. Lett.28B, 493 (1969); For a comprehensive review of the formalism see for example S.M. Bilenky, B. Pontecorvo: Phys. Rep.41, 225 (1978)
2. J.K. Rowley, B.T. Cleveland, R. Davis, in: Solar neutrinos and neutrino astronomy. Homestake (1984), AIP Conf. Proc. n� 126, p. 1; J.N. Bahcall, B.T. Cleveland, R. Davis, J.K. Rowley: Astrophys. J. Lett.292, 179 (1985)
3. W. Hampel: The gallium solar neutrino detector and neutrino oscillations. In: Proc. of the Int. Conf. on Neutrino Physics and Astrophysics, Nordkirchen, p. 530 (1984) ed. K. Kleinknecht, E.A. Paschos
4. V. Barger, K. Whisnant, R.J.N. Phillips: Phys. Rev.D24, 538 (1981)
5. L. Wolfenstein: Phys. Rev.D17, 2369 (1978)