Om Parkash, Umar Bhatti, Hasnain Zafar, and Saeed Hamid. “Demonstrating Competence in Endoscopic Retrograde Cholangiopancreaticography (ERCP): Recently Credentialed operator’s Performance for Deep Biliary Cannulation over 1 Year Period from Tertiary Care Hospital in Pakistan”. Journal of the Pakistan Medical Association, vol. 71, no. 3, Dec. 2020, p. 929, doi:10.47391/JPMA.1219.