Om Parkash; Umar Bhatti; Hasnain Zafar; 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. J Pak Med Assoc 2020, 71, 929.