Pongpittaya, K. “Causal Factors Influencing the Happiness Learning of Bansomdejchaopraya Rajabhat University Students”. Ratchaphruek Journal, vol. 13, no. 1, Apr. 2015, pp. 11-18, https://so05.tci-thaijo.org/index.php/Ratchaphruekjournal/article/view/240941.