Kawattikul, J. “Assessment of Volume and Residuals in Stomach Using High-Frequency Ultrasound Waves in Non-Emergency Surgical Patients with Chronic Kidney Disease”. Thai Journal of Anesthesiology, vol. 51, no. 1, Jan. 2025, pp. 23-34, https://he02.tci-thaijo.org/index.php/anesthai/article/view/273055.