1. Laboratory of Fundamental and Applied Mathematics of Oran (LMFAO), Department of Mathematics, University of Oran 1 Ahmed Benbella, 31000 Oran, Algeria
2. Department of Physics, University of Sciences and Technology of Oran-MB, El Mnaouar, BP 1505, 31000 Oran, Algeria; Laboratory of Fundamental and Applied Mathematics of Oran (LMFAO), Department of Mathematics, University of Oran 1 Ahmed Benbella, 31000 Oran, Algeria