Premanuphan, P., & Funfuengfu, V. (2021). THE STUDY OF MATHEMATICAL LEARNING ACHIEVCEMENT ON GEOMETRIC TRANSFORMATION BY THE GEOMETER’S SKETCHPAD (GSP) FOR MATTAYOMSUKSA 2 STUDENTS . alaya longkorn eview, 11(2), 165-175. etrieved from https://so06.tci-thaijo.org/index.php/var/article/view/248536