@misc{indiciaea7f421fd994e,
  title = {Exacerbations in chronic bronchitis.},
  author = {I Gregg and J M Inglis},
  year = {1969},
  doi = {10.1136/bmj.4.5686.807-c},
  url = {https://pubmed.ncbi.nlm.nih.gov/4311728/},
  note = {Source identifier: 4311728}
}