@misc{indiciae5ba89f634dae,
  title = {Calibration of seismographic systems : USGS stations in the central California network},
  author = {J. H. Healy and M. E. O'Neill},
  year = {1977},
  doi = {10.3133/ofr77736},
  url = {https://pubs.usgs.gov/publication/ofr77736},
  note = {Source identifier: ofr77736}
}