@misc{indiciaefada26a01b0e,
  title = {The refractory ulcer.},
  author = {D W Piper},
  year = {1987},
  doi = {10.1007/bf01658102},
  url = {https://pubmed.ncbi.nlm.nih.gov/3604233/},
  note = {Source identifier: 3604233}
}