Affiliation: | 1. Department of Mathematics, University of Djillali Liabés, BP. 89 Sidi Bel Abbes, 22000, Algeria;2. Faculty of Exact and informatics, Mathematic Department, Hassiba Benbouali university, Chlef, Algeria;3. Laboratoire d’Analyse Non Linéaire et Mathématiques Appliquées, Université de Tlemcen, Tlemcen, Algeria |