@misc{indiciae26a28b73102f,
  title = {Why not extrasystoles?},
  author = {M Calabresi},
  year = {1986},
  doi = {10.1016/0002-9149(86)90643-0},
  url = {https://pubmed.ncbi.nlm.nih.gov/2421570/},
  note = {Source identifier: 2421570}
}