@misc{indiciae0fe5a222a2a3,
  title = {The challenge they offer.},
  author = {J Perry},
  year = {1967},
  doi = {10.1093/ptj/47.4.292},
  url = {https://pubmed.ncbi.nlm.nih.gov/6047734/},
  note = {Source identifier: 6047734}
}