@misc{indiciae0b25daf1ceee,
  title = {Respiratory muscle function, assessment, and training.},
  author = {T H Shaffer and M R Wolfson and V K Bhutani},
  year = {1981},
  doi = {10.1093/ptj/61.12.1711},
  url = {https://pubmed.ncbi.nlm.nih.gov/7312944/},
  note = {Source identifier: 7312944}
}