@misc{indiciaee76a9594c77b,
  title = {Ultrasonic echoes.},
  author = {W Dock and H Feigenbaum},
  year = {1971},
  doi = {10.1161/01.cir.44.3.487-a},
  url = {https://pubmed.ncbi.nlm.nih.gov/5097450/},
  note = {Source identifier: 5097450}
}