(Jaruwan Sonpang) จารุวรรณ สอนแปง, and (Jensamut Sangpan) เจนสมุทร แสงพันธ์. 2018. “TEACHER ROLES FOR SUPPORTING STUDENTS’ GEOMETRIC PROBLEM - SOLVING ABILITIES IN CLASSROOM TAUGHT THROUGH OPEN APPROACH”. Journal of Education and Innovation 19 (4):65-77. https://so06.tci-thaijo.org/index.php/edujournal_nu/article/view/108400.