ชมภู บ. (2010) “Comparisons of Learning Achievements, Analytical Thinking Abilities, Satisfaction with Learning and Teaching, and Learning Retention in the Mathematics Learning Strand Entitled Trigonometrical Ratios of Matthayomsueksa 4 Students Using Courseware Geometer’s Sketchpad Approach (CGS) and the Conventional Teaching Approach”, Academic Journal of Thailand National Sports University. Chonburi, Thailand, 2(1), pp. 155–165. available at: https://he02.tci-thaijo.org/index.php/TNSUJournal/article/view/252168 (accessed: 18 September 2026).