@misc{indiciae9b513b68b87e,
  title = {Heart rate variability: back to the beginning.},
  author = {Tomas Kara and Jiri Nykodym and Virend K Somers},
  year = {2003},
  doi = {10.1046/j.1540-8167.2003.03258.x},
  url = {https://pubmed.ncbi.nlm.nih.gov/12890037/},
  note = {Source identifier: 12890037}
}