Trương Thị Khánh Hà (tác giả phụ) (Khoa Tâm lý học), Measurement Invariance of Personal Well-Being Index (PWI-8) Across 26 Countries; (https://link.springer.com/journal/10902), Journal of Happiness Studies, Springer Publishing, 15 pages, 2016, DOI 10.1007/s10902-016-9795-0.