สุตนนท์ จ. “A Compare of Learning Achievement, Problem Solving and Satisfaction With Learning History Entitled ‘Ayutthaya’s History’ of Mattayomsuksa 2 Between Learning Circle and Project Learning Approach”. RMUTI Journal Humanities and Social Sciences, vol. 2, no. 1, June 2015, pp. 21-31, https://so05.tci-thaijo.org/index.php/RMUTI_SS/article/view/195886.