คูณทา จิมลอน, and พันธ์งาม อมรรัตน์. “A Development of Mathematics Reasoning Ability Through the Heuristics Thinking Model for Prathom Suksa 3 Students of Ban Nongkhun School under Ubon Ratchathani Primary Educational Service Area Office 3”. Ubon Ratchathani Journal of Research and Evaluation 2, no. 1 (August 27, 2021): 62–69. accessed April 12, 2025. https://so06.tci-thaijo.org/index.php/ubonreseva/article/view/250839.