@misc{indiciaeb3737dce1778,
  title = {Bifocal demand pacing.},
  author = {D E Harken},
  year = {1971},
  doi = {10.1378/chest.59.4.355},
  url = {https://pubmed.ncbi.nlm.nih.gov/5551576/},
  note = {Source identifier: 5551576}
}