@misc{indiciae6cb0b6dae5a4,
  title = {Heart rate and the PR interval.},
  author = {C A Bertrand and E O Godbold and T Schussler and I H Pomper and J C Duffy},
  year = {1972},
  url = {https://pubmed.ncbi.nlm.nih.gov/4560962/},
  note = {Source identifier: 4560962}
}