Mahawongkajit, P., and N. Soonthornkes. “Comparative Effectiveness of Lidocaine Sprays Between Sitting and Supine Position for Patients Undergoing Upper Gastrointestinal Endoscopy: A Prospective Randomized Controlled Trial”. Asian Medical Journal and Alternative Medicine, vol. 22, no. -, Aug. 2022, p. S91, https://asianmedjam.com/index.php/amjam/article/view/1288.