@misc{indiciaee8eacc1fbc47,
  title = {Heart vector magnitude. A simple recording system.},
  author = {B Olsson and L Brorson and K Skarvan},
  year = {1971},
  doi = {10.1016/s0022-0736(71)80026-2},
  url = {https://pubmed.ncbi.nlm.nih.gov/4258120/},
  note = {Source identifier: 4258120}
}