1. Department of Computer Engineering, University Institute of Technology, University of Ngaoundéré, P.O. Box 455, Ngaoundéré, Cameroon
2. Department of Mathematics and Statistics, School of Basic and Applied Sciences, Central University of Punjab, Bathinda, Punjab-151001, India
3. Department of Mathematics, Ondokuz Mayis University, Atakum-55200, Samsun, Turkey