Akhtar, Muhammad Usama, et al. “Comparison Between Analgesic Effects of Pre-Operative and Post-Operative Trocar Site Infiltration of Injection Bupivacaine in Elective Laparoscopic Cholecystectomy”. Pakistan Armed Forces Medical Journal, vol. 73, no. SUPPL-1, July 2023, pp. S40-44, https://doi.org/10.51253/pafmj.v73iSUPPL-1.2697.