แสนคมคาย ส. “A Comparisons of English Speaking Ability Using Conversation, Self - Confident Entitled ‘Places’ in English of Matthayomsueksa 2 Students Between Situation Simulation and CO - OP CO - OP (Cooperative Learning) Approaches”. RMUTI Journal Humanities and Social Sciences, vol. 2, no. 1, June 2015, pp. 1-10, https://so05.tci-thaijo.org/index.php/RMUTI_SS/article/view/195868.