First Author:   Quang Nhat Bui Vietnam Academy of Social Sciences, Vietnam buinhatquang@iames.gov.vn   hanoi, Việt Nam   438572735(Phone) 438572735(Fax) Second Author: Trung Xuan Hoang Vietnam Academy of Social Sciences, Vietnam hoangxuantrung3012@gmail.com   1 lieu giai st, ha noi hanoi, Việt Nam   438572735(Phone)