1. C. B. A. McCusker andM. M. Winn:Nuovo Cimento,28, 175 (1963).
2. A. T. Abrosimov, V. I. Zatsepin, V. I. Solovieva, G. B. Kristiansen andP. S. Chikin:Izvest. Akad. Nauk, SSSR, Fiz.,19, 677 (1955).
3. N. A. Porter, T. E. Cranshaw andW. Galbraith:Phil. Mag.,2, Part 19, 900 (1957).
4. J. V. Jelley:Čerenkov Radiation and its Applications, Ch. 9 (London, 1958).
5. A. E. Chudakov, N. M. Nesterova, V. I. Zatsepin andE. I. Tukish:Proc. Moscow Cosmic-Ray Conf., vol.2 (1960), p. 50.