@misc{indiciaebad68a883b8b,
  title = {A wide-range linear beat-by-beat cardiotachometer.},
  author = {W M Caldwell and L D Smith and M F Wilson},
  year = {1970},
  doi = {10.1007/bf02509328},
  url = {https://pubmed.ncbi.nlm.nih.gov/5484858/},
  note = {Source identifier: 5484858}
}