อิสลาม ว., อัศวโสวรรณ จ., and พลหลา ม. “Effects of Cooperative Learning With Math League Technique on Mathemetics Achievement of Grade 9 Students”. JOURNAL OF SOUTHERN TECHNOLOGY, vol. 12, no. 1, May 2019, pp. 44-49, https://so04.tci-thaijo.org/index.php/journal_sct/article/view/103135.