Solanki, Nachiket A, et al. “EVALUATION OF ANALGESIC EFFICACY OF BUPIVACAINE AND ROPIVACAINE GIVEN THROUGH LANDMARK GUIDED ERECTOR SPINAE PLANE BLOCK FOR POST-OPERATIVE PAIN RELIEF IN PATIENTS UNDERGOING LAPAROSCOPIC CHOLECYSTECTOMY”. National Journal of Medical Research, vol. 10, no. 03, Sept. 2020, pp. 144-7, https://njmr.in/index.php/file/article/view/78.