TY  - RPRT
TI  - Gastrointestinal endoscopy.
AU  - J M Orr
PY  - 1993
DO  - 10.5694/j.1326-5377.1993.tb121717.x
UR  - https://pubmed.ncbi.nlm.nih.gov/8450795/
ID  - 8450795
ER  -