1. Department of Mathematics, University of the Punjab, New Campus, Lahore, Pakistan
2. BORDA Research Unit and Multidisciplinary Institute of Enterprise (IME), Universidad de Salamanca, 37007 Salamanca, Spain
3. Department of Mathematics, Faculty of Science and Arts, Muhayl Asser, King Khalid University, K.S.A
4. Department of Mathematics and Computer, Faculty of Science, Ibb University, Ibb, Yemen