@misc{indiciaed1735668c6a5,
  title = {Long-term spectral analysis of heart rate variability--an algorithm based on segmental frequency distributions of beat-to-beat intervals.},
  author = {M Malik and T Cripps and T Farrell and A J Camm},
  year = {1989},
  doi = {10.1016/0020-7101(89)90012-3},
  url = {https://pubmed.ncbi.nlm.nih.gov/2777402/},
  note = {Source identifier: 2777402}
}