1. Faculty of Fundamental Science, Industrial University of Ho Chi Minh City, Ho Chi Minh City, Vietnam
2. Department of Mathematics, Faculty of Science and Letters, Aǧri Ibrahim Cecen University, Agri 04100, Turkey
3. Faculty of Math, FPT University HCM, Saigon Hi-Tech Park, Thu Duc City, Ho Chi Minh City, Vietnam
4. Division of Applied Mathematics, Thu Dau Mot University, Binh Duong Province, Vietnam