TEKİN, Ercüment H., et al. “Effect of Morphine, Ketorolac and Tenoxicam on Postoperative Small Intestinal Ileus in Rats”. Turkish Journal of Gastroenterology, vol. 10, no. 2, Jan. 1999, pp. 143-6, https://www.turkjgastroenterol.org/index.php/tjg/article/view/966.