Ghazanfar, A., and A. Asghar. “Comparison of High Versus Low Intra-Peritoneal Carbon Dioxide Pressure on Abdominal Pain, Hemodynamic Symptoms and Liver Function Tests in Patients Undergoing Laparoscopic Cholecystectomy”. Journal of Rawalpindi Medical College, Vol. 23, no. 2, May 2019, pp. 85-88, http://www.journalrmc.com/index.php/JRMC/article/view/1103.