TY  - RPRT
TI  - "Open-access" upper gastrointestinal endoscopy.
AU  - K B Orr
PY  - 1986
DO  - 10.5694/j.1326-5377.1986.tb112335.x
UR  - https://pubmed.ncbi.nlm.nih.gov/3713597/
ID  - 3713597
ER  -