Siriphot, Thanyanut, and Sunchai Hamcumpai. “The Effect of Cooperative Learning on Students’ Speaking Self-efficacy”. KKU Research Journal (Graduate Studies) Humanities and Social Sciences 8, no. 2 (August 30, 2020): 145–154. accessed September 14, 2026. https://so04.tci-thaijo.org/index.php/gskkuhs/article/view/245330.