D. T. K. Grewal, D. B. Kaur, D. P. Kumar, and D. S. Kaur, “Comparison of Ropivacaine 0.2% Alone and in Combination with Fentanyl for Caudal Anesthesia in Paediatric Patients”, ijirms, vol. 4, no. 02, p. 103 to 107, Feb. 2019.