@misc{indiciae2fd93816c8a3,
  title = {Are sleep studies necessary in COPD?},
  author = {N J Douglas},
  year = {1990},
  doi = {10.1007/bf02718231},
  url = {https://pubmed.ncbi.nlm.nih.gov/2117215/},
  note = {Source identifier: 2117215}
}