Thupthein, Pongsupa, Songchai Ugsonkid, and Chanon Chuntra. “The Study of Grade 11 Students’ Problem-Solving Ability on Sequences and Series by Using Teaching Through Problem Solving”. Interdisciplinary Academic and Research Journal 6, no. 3 (May 10, 2026): e291376. accessed September 28, 2026. https://so03.tci-thaijo.org/index.php/IARJ/article/view/291376.