@misc{indiciaed14ad3153881,
  title = {Open access upper gastrointestinal endoscopy.},
  author = {R V Heatley},
  year = {1993},
  doi = {10.1136/bmj.306.6887.1224},
  url = {https://pubmed.ncbi.nlm.nih.gov/8499851/},
  note = {Source identifier: 8499851}
}