1. Department of Mathematics, Faculty of Science, Nong Lam University , Ho Chi Minh City , Vietnam
2. Falculty of Maths, FPT University HCM, Saigon Hi-tech Park , Ho Chi Minh City , Vietnam
3. Division of Applied Mathematics, Science and Technology Advanced Institute, Van Lang University , Ho Chi Minh City , Vietnam
4. Faculty of Applied Technology, School of Engineering and Technology, Van Lang University , Ho Chi Minh City , Vietnam