@misc{indiciaed6b8ff1a933a,
  title = {Difficult asthma.},
  author = {P J Barnes and K F Chung},
  year = {1989},
  doi = {10.1136/bmj.299.6701.695},
  url = {https://pubmed.ncbi.nlm.nih.gov/2508876/},
  note = {Source identifier: 2508876}
}