@misc{indiciae941199dfd96b,
  title = {Breathlessness during exercise in COPD: how do the drugs work?},
  author = {P M A Calverley},
  year = {2004},
  doi = {10.1136/thx.2004.023150},
  url = {https://pubmed.ncbi.nlm.nih.gov/15170021/},
  note = {Source identifier: 15170021}
}