@misc{indiciae33117ce10af7,
  title = {Orientation in endoscopy.},
  author = {L I Epstein},
  year = {1981},
  doi = {10.1055/s-2007-1021652},
  url = {https://pubmed.ncbi.nlm.nih.gov/7227332/},
  note = {Source identifier: 7227332}
}