Wattanarungsan, P. “Foreign Bodies in the Esophagus - วัตถุแปลกปลอมในหลอดอาหาร”. Journal of Health Science of Thailand, vol. 17, no. Sup.3, Nov. 2018, pp. SIII683-689, https://thaidj.org/index.php/JHS/article/view/5109.