Sonya K, C. V. D. A prospective randomised double blind study of the comparison of two opioids- fentanyl and buprenorphine – as adjuvant to spinal bupivacaine in caesarean sections. Int J Clin Trials [Internet]. 2017 Jan. 25 [cited 2025 Oct. 6];4(1):45-8. Available from: https://www.ijclinicaltrials.com/index.php/ijct/article/view/180