อุปทุม วัชราภรณ์. 2015. “The Comparison of Learning Achievement, Analytical Thinking and Attitudes Toward Mathematics Entitled Ratio and Percentage of Matthayomsueksa 2 Students Between Using Constructivist Learning Activities and CIPPA Learning Activities”. RMUTI Journal Humanities and Social Sciences 2 (2):24-36. https://so05.tci-thaijo.org/index.php/RMUTI_SS/article/view/195434.