@misc{indiciae45ab6d5758f8,
  title = {A high resolution ultrasonic microscope.},
  author = {A Penttinen and M Luukkala},
  year = {1977},
  doi = {10.1016/0041-624x(77)90082-8},
  url = {https://pubmed.ncbi.nlm.nih.gov/898384/},
  note = {Source identifier: 898384}
}