Comparison Of Hyperbaric Ropivacaine With Fentanyl Versus Hyperbaric Bupivacaine With Fentanyl In Elective Surgical Patients Undergoing Lower Abdominal Surgery Under Spinal Anaesthesia. Int. J. Environ. Sci. Published online September 10, 2025:4519-4526. doi:10.64252/shvm3s28