Zabetian,H , , Rahmanian,M , , Tadayon,N , and Kalani,N . "Comparison of pain with bupivacaine and bupivacaine-sufentanil combination in women undergoing cesarean section with spinal anesthesia: A double-blind randomized clinical trial", The Iranian Journal of Obstetrics, Gynecology and Infertility, 25, 8, 2022, 8-18. doi: 10.22038/ijogi.2022.21195