BAKAN, N., S. SAYDAM, and A. GUREL. “Caudal Epidural Morphine in Chidren for Postoperative Analgesia”. Annals of Medical Research, vol. 5, no. 2, May 2021, pp. 0158-61, http://annalsmedres.org/index.php/aomr/article/view/2682.