@misc{indiciae45c83cd471d2,
  title = {An accurate lead system for spatial vectorcardiography.},
  author = {R A HELM},
  year = {1957},
  doi = {10.1016/0002-8703(57)90176-x},
  url = {https://pubmed.ncbi.nlm.nih.gov/13402701/},
  note = {Source identifier: 13402701}
}