Boonnan, Rungrat. “Development of a Positive Psychology-Based Program to Promote Self-Directed Learning for Grade 8 Students”. Chophayom Journal 37, no. 2 (August 17, 2026): 89–104. accessed September 2, 2026. https://so01.tci-thaijo.org/index.php/ejChophayom/article/view/289818.