1. aDivision 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. Department of Mathematics, Arak Branch, Islamic Azad University, Arak, Iran