1. Department of Mathematics, Faculty of Sciences, Ferhat-Abbas University of Sétif 1, Sétif 19000, Algeria
2. Fundamental and Numerical Mathematics Laboratory (LMFN), Ferhat-Abbas University, Sétif 19000, Algeria
3. Laboratoire de Mathématiques Nicolas Oresme, Université de Caen, Campus II, Boulevard Maréchal Juin, B.P. 5186, 14032 Caen, France