Meekhamthong, Pikul. 2020. “The Development of Instructional Model base on Constructivist Theory in conjunction with The STAD Cooperative Learning for Enhancing in The Matical Problem Solving Ability on Fractions and Decimals for The Students in Seventh Grade”. Dhammathas Academic Journal 20 (3):161-72. https://so06.tci-thaijo.org/index.php/dhammathas/article/view/196927.