Hassan, Lt Col Fayyaz, et al. “ENDOSCOPIC MANAGEMENT OF COMMON BILE DUCT STONES EXPERIENCE AT MILITARY HOSPITAL, RAWALPINDI: Endoscopic Management of Bile Duct Stones”. Pakistan Armed Forces Medical Journal, vol. 60, no. 3, Sept. 2010, pp. 377-81, https://pafmj.org/PAFMJ/article/view/1355.