@misc{indiciaef71e9878185e,
  title = {A general-purpose computer program for studying ultrasonic beam patterns generated with acoustic lenses},
  author = {Roberti, Dino and Ludwig, Reinhold and Looft, Fred J.},
  year = {1988},
  url = {https://ntrs.nasa.gov/citations/19880051890},
  note = {Source identifier: 19880051890}
}