@misc{indiciae8476295ac70e,
  title = {Concealed extrasystoles.},
  author = {W S Breall},
  year = {1970},
  doi = {10.1016/0002-9149(70)90606-5},
  url = {https://pubmed.ncbi.nlm.nih.gov/4191760/},
  note = {Source identifier: 4191760}
}