1. A. N. Tavkhelidze, Rapporteur Talk at 15th International Conference on High Energy Physics, Kiev, August?September, 1970 (Preprint JINR-5454, Dubna, 1971).
2. A. A. Logunov and A. N. Tavkhelidze, Nuovo Cimento,29, 380 (1963).
3. V. G. Garsevanishvili, V. A. Matveev, L. A. Slepchenko, and A. N. Tavkhelidze, Talk at the Coral Gables Conference, Miami, 1969; Phys. Lett.,29B 1919 (1969); see also: Problems of Elementary-Particle and Nuclear Physics [in Russian], Vol. 1, Atomizdat (1970), pp. 93?130.
4. S. P. Alliluyev, S. S. Gershtein, and A. A. Logunov, Phys. Lett.,18, 196 (1965).
5. A. A. Logunov and O. A. Khrustalev, Preprint STF-69-20, STF-69-21 [in Russian], Institute of High Energy Physics, Serpukhov (1969); see also; Problems of Elementary-Particle and Nuclear Physics [in Russian], Vol. 1, No. 1, Atomizdat (1970), pp. 71?90.