Tayyiba Akhter , Junaid Khan Lodhi, Asim Malik , Rana Shakil Ahmad. “240 Original Article Ultrasound Scoring System for Pre-Operative Anticipation of Difficult Laparoscopic Cholecystectomy”. Journal of Rawalpindi Medical College (September 30, 2018). Accessed April 24, 2024. http://journalrmc.com/index.php/JRMC/article/view/925.