@misc{indiciaea61b13c2b144,
  title = {Letter: Concealed ventricular extrasystoles.},
  author = {P R Lightfoot},
  year = {1975},
  doi = {10.1016/0002-9149(75)90096-x},
  url = {https://pubmed.ncbi.nlm.nih.gov/53995/},
  note = {Source identifier: 53995}
}