Premanuphan, Phanittida, and Varinporn Funfuengfu. “HE TUDY F ATHEMATICAL EARNING CHIEVCEMENT N EOMETRIC RANSFORMATION Y HE GEOMETER’S KETCHPAD (GSP) OR ATTAYOMSUKSA TUDENTS ”. Valaya Alongkorn Review 11, no. 2 (August 30, 2021): 165-175. ccessed November 30, 2021. https://so06.tci-thaijo.org/index.php/var/article/view/248536.