1. Department of Mathematics, College of Science King Saud University, Riyadh, Saudi Arabia
2. Department of Mathematics, Government College University, Faisalabad, Pakistan
3. Department of Mathematics, Faculty of Science and Arts, Düzce University, Düzce, Turkey
4. Section of Mathematics, International Telematic University Uninettuno, CorsoVittorio Emanuele II, 39, 00186 Roma, Italy
5. Department of Mathematics, COMSATS University Islamabad, Islamabad, Pakistan