Awae, P., A. Chomchuen, and A. Sama-ae. “Effects of Learning Management by Concept Attainment Process on Concept of and Achievement in Mathematics”. KASEM BUNDIT JOURNAL, vol. 19, no. 2, Dec. 2018, pp. 108-24, https://so04.tci-thaijo.org/index.php/jkbu/article/view/160684.