Sangeeta Varun, and Tuhin Vashishth. “Haemodynamic Comparison Between Isobaric Bupivacaine Fentanyl and Isobaric Ropivacaine Fentanyl for Lower Abdomoinaland Lower Limb Surgery”. Academia Anesthesiologica International, Vol. 4, no. 2, Oct. 2019, pp. 184-8, doi:10.21276/aan.2019.4.2.42.