@misc{indiciae51475836f4b3,
  title = {Prototype ultrasonic instrument for quantitative testing},
  author = {Lynnworth, L. C. and Dubois, J. L. and Kranz, P. R.},
  year = {1972},
  url = {https://ntrs.nasa.gov/citations/19730008835},
  note = {Source identifier: 19730008835}
}