@misc{indiciaee8735535a19c,
  title = {Instant electrocardiograms as a teaching aid.},
  author = {M I Ferrer},
  year = {1969},
  doi = {10.1378/chest.56.4.344},
  url = {https://pubmed.ncbi.nlm.nih.gov/4186003/},
  note = {Source identifier: 4186003}
}