@misc{indiciae73600f9be595,
  title = {Improved phonocardiogram system based on acoustic impedance matching.},
  author = {R S Schwartz and J T Reeves and I E Sodal and F S Barnes},
  year = {1980},
  doi = {10.1152/ajpheart.1980.238.4.h604},
  url = {https://pubmed.ncbi.nlm.nih.gov/7377335/},
  note = {Source identifier: 7377335}
}