@misc{indiciae3fd5bb57199f,
  title = {Heart-rate variability.},
  author = {A J Mearns and D A Brodie and G D Unsworth},
  year = {1977},
  doi = {10.1016/s0140-6736(77)90042-3},
  url = {https://pubmed.ncbi.nlm.nih.gov/69131/},
  note = {Source identifier: 69131}
}