@misc{indiciae9b4551fd78c8,
  title = {Errors in performance and interpretation of echocardiograms.},
  author = {R E Kerber},
  year = {1973},
  doi = {10.1002/jcu.1870010410},
  url = {https://pubmed.ncbi.nlm.nih.gov/4210075/},
  note = {Source identifier: 4210075}
}