@misc{indiciaef029608749e0,
  title = {COPD exacerbations. 4: Prevention.},
  author = {S Scott and P Walker and P M A Calverley},
  year = {2006},
  doi = {10.1136/thx.2005.041848},
  url = {https://pubmed.ncbi.nlm.nih.gov/16648352/},
  note = {Source identifier: 16648352}
}