Dr. Arjun Gotagunaki, Dr. Varsha Patil, Dr. Jyothsna Paranjape and Dr. Kunal Uday Patil 2026. A Comparative Study on the Efficacy of Epidural Tramadol versus Fentanyl as Adjuvants to Ropivacaine in Postoperative Pain Management. International Journal of Pharmacy Research & Technology (IJPRT). 16, 2 (Aug. 2026), 5018–5023.