Institution: | 1.Laboratory LAMA, Department of Mathematics, Faculty of Sciences Dhar El Mahraz, University of Fez, P.O. Box 1796, Atlas, 30000, Fez, Morocco ;2.Department of Mathematics (AMNEA Group), Faculty of Sciences and Technics, Moulay Ismail University, P.O. Box 509, Boutalamine, Errachidia, 52000, Morocco ;3.Laboratory LIPOSI, National School of Applied Sciences, University Hassan 1, 25000, Khouribga, Morocco ; |