Kositworakitkun , Y. “Intravenous Ketamine for Postoperative Pain Control in Spine Surgery: a Randomized Controlled Study”. Thai Journal of Anesthesiology, vol. 51, no. 2, Mar. 2025, pp. 109-16, https://he02.tci-thaijo.org/index.php/anesthai/article/view/274053.