1. F Vodop'yanov, A. Kuzmin et al., Proc. Inter. Conf. High-Energy Accelerators and Instrumention. CERN, Geneva, p. 470, 477 (1959).
2. G. S. Kazanskii, A. I. Mikhailov, and A. P. Tsarenkov, OIYaI Preprint B-50-819, Dubna (1961).
3. V. I. Kotov, A. B. Kuznetsov, and N. B. Rubin, ?Usp. fiz. nauk?64, 197 (1958).
4. M. S. Rabinovich, ?Tr. FIAN?10, 23 (1958).
5. S. K. Esin et al., OIYaI Preprint R-555. Dubna (1960).