TY  - RPRT
TI  - Objective evaluation of ERCP procedures: a simple grading scale for evaluating technical difficulty.
AU  - K Ragunath
AU  - L A Thomas
AU  - W Y Cheung
AU  - P D Duane
AU  - D G Richards
PY  - 2003
DO  - 10.1136/pmj.79.934.467
UR  - https://pubmed.ncbi.nlm.nih.gov/12954961/
ID  - 12954961
ER  -