@misc{indiciae07135c498f71,
  title = {Speaking tubes for bedside use.},
  author = {M Armstrong and P L Efros},
  year = {1996},
  doi = {10.1016/s0194-5998(96)70020-7},
  url = {https://pubmed.ncbi.nlm.nih.gov/8969770/},
  note = {Source identifier: 8969770}
}