Srisukhumchai, N., and S. Thienthong. “First Year Residents’ Knowledge and Practice Related to Postoperative Pain Management”. Srinagarind Medical Journal, vol. 31, no. 2, Apr. 2016, pp. 145-50, https://li01.tci-thaijo.org/index.php/SRIMEDJ/article/view/55901.