1. Laboratory of PDEs, Algebra and Spectral Geometry, Department of Mathematics, Faculty of Sciences, Ibn Tofail University, Kénitra, Morocco
2. ENSC, Ibn Tofail University, Kénitra, Morocco
3. Department of Mathematics, Linnaeus University, Växjö, Sweden
4. Department of Mathematics, Faculty of Polydisciplinary, Sultan Moulay Slimane University, Khouribga, Morocco