@misc{indiciae3a5ce3396964,
  title = {Shock wave data and the study of the earth.},
  author = {Ahrens, T. J. and Petersen, C. F.},
  year = {1969},
  url = {https://ntrs.nasa.gov/citations/19690062199},
  note = {Source identifier: 19690062199}
}