1. Department of Mathematics, Division of Science and Technology, University of Education, Lahore 54590, Pakistan
2. Physics Department, De La Salle University, 2401 Taft Avenue, Manila 1004, Philippines
3. Physics Department, Mapúa University, 658 Muralla St., Intramuros, Manila 1002, Philippines
4. Physics Department, Eastern Mediterranean University, Famagusta, 99628 North Cyprus via Mersin 10, Turkey