1. M. V. S. Chandrasekhar Rao, G. Sree Krishna Murthy, K. Radha Krishna, S. Bhuloka Reddy, G. Satyanarayana, C. V. Raghavaiah, D. L. Sastry andS. N. Chintalapudi:Z. Phys. A,335, 25 (1990).
2. G. Sree Krishna Murthy, M. V. S. Chandrasekhar Rao, K. Radha Krishna, S. Bhuloka Reddy, G. Satyanarayana, P. V. Ramana Rao, D. L. Sastry andS. N. Chintalapudi:J. Phys. G,16, 1095 (1990).
3. N. V. S. Vara Prasad, G. Sree Krishna Murthy, M. V. S. Chandrasekhar Rao, G. Satyanarayana, D. L. Sastry andS. N. Chintalapudi: accepted for publication inJ. Phys. G (1993).
4. R. K. Gupta andS. Jha:Nuovo Cimento,14, 88 (1956).
5. B. K. Das Mahapatra andP. Mukherjee:J. Phys, A,7, 388 (1974).