Wnęk, Włodzimierz, Renata Zajączkowska, Walery Sienkiel, and Sławomir Snela. 2005. “Postoperative Pain Treatment With Continuous Epidural Analgesia After Spinal Fusion Surgery”. European Journal of Clinical and Experimental Medicine 3 (1):49–51. https://journals.ur.edu.pl/ejcem/article/view/13485.