Rerknimitr, R., T. Akaraviputh, T. Ratanachu-Ek, P. Kongkam, N. Pausawasdi, and P. Pisespongsa. “Current Status of GI Endoscopy in Thailand and Thai Association of Gastrointestinal Endoscopy (TAGE)”. Siriraj Medical Journal, vol. 70, no. 5, Oct. 2018, pp. 476-8, https://he02.tci-thaijo.org/index.php/sirirajmedj/article/view/152789.