Summart, Preeyaphatsanakorn, and Nongluk Viriyapong. 2021. “Development of Mathematics Learning Activities Using KWDL Technique to Promote Mathematical Problem Solving Abilities and Learning Achievement on Percentage Problem Topic of Grade 6 Students”. Journal of Roi Et Rajabhat University 15 (1):75-86. https://so03.tci-thaijo.org/index.php/reru/article/view/240361.