1. Department of Mathematics, COMSATS Institute of Information Technology, Kamra Road, Attock 43600, Pakistan e-mail:
2. Institute of Applied Mathematics (LSIII), TU Dortmund, Vogelpothsweg 87, Dortmund D-44227, Germany
3. Professor Fellow of Bangladesh Academy of Science Department of Mathematics, University of Dhaka, Dhaka 1000, Bangladesh
4. Department of Automotive and Marine Engineering Technology, College of Technological Studies, The Public Authority for Applied Education and Training, Kuwait 13092, Kuwait