First Author:   Bao C.N. To University of Economics Ho Chi Minh City, Vietnam baotcn@ueh.edu.vn         Second Author: Nham T.H. Nguyen University of Economics Ho Chi Minh City, Vietnam nhamnth@ueh.edu.vn         Third Author: Bao K.Q. Nguyen University of Economics Ho Chi Minh City, Vietnam nguyenbao@ueh.edu.vn         Fourth Author: Tam T.H. Le Nam Dinh University of Technology Education, Vietnam lethihongtam0106@gmail.com