@misc{indiciae5756b5512ad8,
  title = {Sonic impedance technique detects flaws in polyurethane foam spray-on insulation},
  author = {Haralson, H. S. and Haynes, J. L.},
  year = {1970},
  url = {https://ntrs.nasa.gov/citations/19700000012},
  note = {Source identifier: 19700000012}
}