Q. A. Bhatti
Department of Physics, Shah Abdul Latif University, Khairpur, Pakistan
B. A. Malik
Department of Physics, Shah Abdul Latif University, Khairpur, Pakistan
A. H. Bhatti
Department of Physics, Shah Abdul Latif University, Khairpur, Pakistan
A. A. Bhutto
Department of Physics, Government Degree & Postgraduate College Larkana, Sindh, Pakistan