Ratanasuwan, P., Nonphiaraj, S., Pongjanyakul, S., Somdee, W. and Taesiri, W. (2015) “Efficacy of Combination of Ketamine and Morphine for Intravenous Patient Controlled- Analgesia in Upper Abdominal Surgery at Srinagarind Hospital”, Srinagarind Medical Journal, 30(5), p. 67. Available at: https://li01.tci-thaijo.org/index.php/SRIMEDJ/article/view/40017 (Accessed: 29 March 2024).