Ariyanuchitkul, T., N. Petchdee, and J. Hongboon. “Postoperative Analgesia after Intrathecal Morphine in Orthopedic Surgery”. Maharat Nakhon Ratchasima Hospital Journal, vol. 26, no. 1, Oct. 2024, pp. 19-28, https://he04.tci-thaijo.org/index.php/MNRHJ/article/view/2152.