1. University of Bamenda, Cameroon
2. Department of Physics, Faculty of Sciences, University of Dschang, Cameroon
3. Unité de Recherche d’Automatique et Informatique Apliquee (UR-AIA), Department of Telecommunication and Network Engineering, Fotso Victor University Institute of Technology, P. O. Box 134 Bandjoun, Cameroon
4. Department of Mathematics, Firat University, Elazig, Turkey
5. Department of Medical Research, China Medical University Taichung, Taiwan
6. Department of General and Scientific Studies, University of Dschang, IUT-FV Bandjoun, Cameroon
7. Department of Electrical and Electronic Engineering, NAHPI, University of Bamenda, Cameroon
8. Nonlinear Physics and Complex Systems Group, Department of Physics, The Higher Teachers’ Training College, University of Yaoundé I, P. O. Box 47 Yaoundé, Cameroon