@misc{indiciae964f68e85cbd,
  title = {Overcoming sphincteric resistance during endoscopy.},
  author = {M Freud and A Weissler},
  year = {1977},
  doi = {10.1056/nejm197702032960519},
  url = {https://pubmed.ncbi.nlm.nih.gov/831117/},
  note = {Source identifier: 831117}
}