Boonpeng, P., K. Yingkayun, U. Boonliam, and C. Jaisin. “Development of Carbon Dioxide Concentration Control System for an Air-Conditioned Room”. Science and Engineering Connect, vol. 45, no. 2, June 2022, pp. 215-33, https://ph04.tci-thaijo.org/index.php/SEC/article/view/10281.