@misc{indiciae392c95dc9221,
  title = {Another problem with an expiratory valve.},
  author = {A W Murray and J C Easton},
  year = {1988},
  doi = {10.1111/j.1365-2044.1988.tb05614.x},
  url = {https://pubmed.ncbi.nlm.nih.gov/3202306/},
  note = {Source identifier: 3202306}
}