A clinical prospective, randomized study to compare intrathecal isobaric bupivacaine – fentanyl and isobaric ropivacaine – fentanyl for lower abdominal and lower limb surgeries - Varun, Sangeeta; Srivastava, Mridul; Maurya, Indubala; Garg, Rakesh; Dhama, Vipin; Mani, Yogesh Kumar (Anaesthesia, Pain & Intensive Care, 2019)