1. Institute of Research and Development, Duy Tan University, Da Nang, Vietnam
2. Department of Mathematics and Computer Science, University of Science, Ho Chi Minh City, Vietnam
3. Vietnam National University, Ho Chi Minh City, Vietnam
4. Faculty of Basic Science, Posts and Telecommunications Institute of Technology, Ho Chi Minh City, Vietnam
5. Applied Analysis Research Group, Faculty of Mathematics and Statistics, Ton Duc Thang University, Ho Chi Minh City, Vietnam