@misc{indiciae55b5e9478346,
  title = {Aeromagnetic map of the Santa Ana 1:100,000 scale quadrangle, California},
  author = {Robert C. Jachens and Eleanor T. Dixon},
  year = {1991},
  doi = {10.3133/ofr91393},
  url = {https://pubs.usgs.gov/publication/ofr91393},
  note = {Source identifier: ofr91393}
}