1. Division of Applied Mathematics, Thu Dau Mot University, Thu Dau Mot City, Binh Duong Province, Vietnam + Department of Mathematics, Çankaya University, Etimesgut, Ankara, Turkey + Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan
2. Laboratory of Mathematics, Djillali Liabes University of Sidi Bel-Abbes, Sidi Bel Abbes, Algeria