Sureshbabu K, Sasirekha D, Manivannan P, Kayalvizhi P, and Shankar R, “Comparative Study of Ropivacaine-Fentanyl Versus Bupivacaine-Fentanyl for Epidural Labour Analgesia -Prospective Randomised Control Study”, Natl J Med Res, vol. 16, no. 04, pp. 200–205, Oct. 2026.