Promchan, R., and C. Leethanakul. “Increasing the Efficiency of Relapse Prevention After Orthodontic Treatment by Biological Retention”. Thai Journal of Orthodontics, vol. 8, no. 2, Sept. 2020, pp. 40-51, https://he01.tci-thaijo.org/index.php/THAIORTHO/article/view/249600.