theerasopon, P., and W. Ritthagol. “Historical Social Perspective and Incidence of Cleft Lip and/Or Palate”. Thai Journal of Orthodontics, vol. 9, no. 2, Sept. 2020, pp. 26-32, https://he01.tci-thaijo.org/index.php/THAIORTHO/article/view/249537.