G. Draisci, MD, L. Frassanito, MD, R. Pinto, MD, B. Zanfini, MD, G. Ferrandina, MD, and A. Valente, MD, “Safety and effectiveness of coadministration of intrathecal sufentanil and morphine in hyperbaric bupivacaine-based spinal anesthesia for cesarean section”, J of Opioid Management, vol. 5, no. 4, pp. 197–202, Jan. 2018.