Phuong, N. N., and T. T. M. P. Ths. “Factors under the Influence of the Elderly Tourists’ Motive in Vietnam: Study in Hanoi”. The International Journal of Humanities & Social Studies, vol. 7, no. 3, Mar. 2019, doi:10.24940/theijhss/2019/v7/i3/HS1903-049.