Sombutboon J, Prakas N, Eiu-Seeyok B. Happiness of Thai Elderly in Thailand 4.0. JPNC [Internet]. 2019 Jun. 29 [cited 2024 Apr. 25];30(2):219-28. Available from: https://he01.tci-thaijo.org/index.php/pnc/article/view/199567