Wilkinson, T., P. Mehrotra, P. Y. Bansod, and A. Murtaza. “Three Port Versus Four Port Laparoscopic Cholecystectomy- a Prospective Study”. International Journal of Medical Research and Review, Vol. 5, no. 3, Mar. 2017, pp. 235-41, doi:10.17511/ijmrr.2017.i03.04.