@misc{indiciae34dab46152e7,
  title = {Variation of P-wave velocity before the Bear Valley, California, earthquake of 24 February 1972},
  author = {R. Robinson and R. L. Wesson and W.L. Ellsworth},
  year = {1974},
  doi = {10.1126/science.184.4143.1281},
  url = {https://pubs.usgs.gov/publication/70011057},
  note = {Source identifier: 70011057}
}