1. W.H. Barkas, Nuclear Research Emulsion (Academia Press, London, 1963).
2. M.M. Sherif, M. Mohery, Egypt. J. Phys. 22, 125 (1991)
3. A. El-Naghy et al., Nuovo Cimento A 110, 125 (1997)
4. F.H. Liu, Chin. J. Phys. 38, 1063 (2000)
5. M. Mohery, N.N. Abd-Allah, Int. J. Mod. Phys. E 11, 161 (2002)