Rahat Dahmardeh, A., A. Keykha, and N. Bamerian. “Effect of Using Low-Dose Ketamine After Spinal Anesthesia on the Severity of Postoperative Pain in Patients With Orthopedic Surgery”. Archives of Anesthesiology and Critical Care, Vol. 3, no. 4, Oct. 2017, pp. 378-81, http://aacc.tums.ac.ir/index.php/aacc/article/view/131.