@misc{indiciae8fa119bcb7f1,
  title = {Mainstem extrasystoles.},
  author = {H J MARRIOTT and S M BRADLEY},
  year = {1957},
  doi = {10.1161/01.cir.16.4.544},
  url = {https://pubmed.ncbi.nlm.nih.gov/13461263/},
  note = {Source identifier: 13461263}
}