@misc{indiciae802caab8b7b5,
  title = {Research into bronchitis and emphysema.},
  author = {C M Fletcher and N L Jones and E J Campbell},
  year = {1968},
  doi = {10.1136/pgmj.44.507.48},
  url = {https://pubmed.ncbi.nlm.nih.gov/5639228/},
  note = {Source identifier: 5639228}
}