@misc{indiciae90cea5b8f9ab,
  title = {Spirometry using motivational techniques.},
  author = {A Palmer and W R Ayers and S Abraham and M Wilbur},
  year = {1971},
  doi = {10.1016/0021-9681(71)90067-1},
  url = {https://pubmed.ncbi.nlm.nih.gov/5159905/},
  note = {Source identifier: 5159905}
}