Simajareuk, S., Yimyaem, P.R., Sorasit, C., Kaijanad, J. and Suwanatri, K. 2014. Analgesic Efficacy of Postoperative Pain Management Following Upper Abdominal Surgery in Srinagarind Hospital. Srinagarind Medical Journal. 29, 3 (Jul. 2014), 269–275.