1. A. H. Choudhury:
Physics Department, University of Dacca, Dacca, East-Pakistan
2. D. Husain:
Physics Department, University of Dacca, Dacca, East-Pakistan
3. A. L. Choudhury:
Physics Department, University of Dacca, Dacca, East-Pakistan
4. A. K. Rafiqullah:
Physics Department, University of Dacca, Dacca, East-Pakistan