1. S. G. H. Taqvi:
Institute of Pure & Applied Physics, University of Karachi, Karachi, Pakistan
2. M. A. R. Khan:
Institute of Pure & Applied Physics, University of Karachi, Karachi, Pakistan
3. P. R. Jafery:
Institute of Pure & Applied Physics, University of Karachi, Karachi, Pakistan
4. S. H. Baqar:
Institute of Pure & Applied Physics, University of Karachi, Karachi, Pakistan