@misc{indiciaec649e1f367a6,
  title = {PR interval in the aged.},
  author = {A N Clark and A H Craven},
  year = {1981},
  doi = {10.1093/ageing/10.3.157},
  url = {https://pubmed.ncbi.nlm.nih.gov/7270323/},
  note = {Source identifier: 7270323}
}