Numjaitaharn, S., P. Tharnprisan, R. Rongtonggul, P. Chouwajaroen, W. Prasertcharoensuk, and S. Thienthong. “A Postoperative Pain Survey in the Second Day After Cesarean Section”. Srinagarind Medical Journal, vol. 21, no. 1, Nov. 2013, pp. 9-16, https://li01.tci-thaijo.org/index.php/SRIMEDJ/article/view/13201.