1. Peters, B., Proc. Jaipur Conf. Cosmic Rays (in the press).
2. Subramanian, A., Ph.D. thesis, Univ. Madras (1962).
3. Lal, S., Raghavan, R., Rangaswamy, T. N., Sreekantan, B. V., and Subramanian, A., Proc. Jaipur Conf. Cosmic Rays (in the press).
4. Brooke, G., Meyer, M. A., and Wolfendale, A. W., Proc. Phys. Soc. (in the press).
5. Barrett, P. H., Bollinger, L. M., Cocconi, G., Eisenberg, Y., and Greisen, K., Rev. Mod. Phys., 24, 133 (1952).