1. J.H. Christenson, J.W. Cronin, V.L. Fitch, R. Turlay, Phys. Rev. Lett. 13 (1964) 138; V.L. Fitch, Rev. Mod. Phys. 53 (1981) 387.
2. Particle Data Group, Eur. Phys. J. C3 (1998) 1.
3. J.S. Bell, J. Steinberger, in: R.G. Moorhouse, A.E. Taylor, T.R. Walsh (Eds.), Proceedings of the Oxford International Conference on Elementary Particles, Rutherford Lab., 1965, p. 195.
4. M. Baldo-Ceolin, V.V. Barmin, V.G. Barylov, G.V. Davidenko, V.S. Demidov, A.G. Dolgolenko, E. Calimani, F. Mattioli, A.G. Meshkovskii, G. Miari, L.B. Okun, A. Sconza, S. Ciampolillo, I.V. Chuvilo, V.A. Shebanov, JETP Lett. 38 (1983) 557; V.V. Barmin, V.G. Barylov, I.V. Chuvilo, G.V. Davidenko, V.S. Demidov, A.G. Dolgolenko, A.G. Meshkovskii, L.B. Okun, V.A. Shebanov, M. Baldo-Ceolin, E. Calimani, S. Ciampolillo, F. Mattioli, G. Miari, A. Sconza, Nucl. Phys. B 247 (1984), 293; B 254 (1985) 747 (Erratum); L.B. Okun, hep-ph/9612247, Proceedings of the Workshop on K Physics, Orsay, France, 30 May–4 June, 1996.
5. CPLEAR Collaboration, Proceedings of the IHEP 98, Vancouver 1998, to appear.