1. P. Minkovski and W. Ochs, Eur. Phys. J. C 9, 283 (1999).
2. V. V. Vereshchagin, K. N. Mukhin, and O. O. Patarakin, Usp. Fiz. Nauk 170, 353 (2000).
3. K. Takamatsu et al., in Proceedings of the International Workshop on e +e− Collisions from φ to J/ψ, Novosibirsk, 1999, Ed. by G. V. Fedotovich and S. I. Redin (BINP, Novosibirsk, 2000), p. 163; Nucl. Phys. A 675, 312c (2000);
4. Prog. Theor. Phys. 102, E52 (2001).
5. J. Gunter, A. R. Dzierba, et al., Phys. Rev. D 64, 072003 (2001).