@misc{indiciaea1b48fc452d4,
  title = {Preliminary Digital Geologic Map of the Santa Ana 30' x 60' Quadrangle, Southern California},
  author = {D. M. Morton and Rachel M. digital preparation by Hauser and Kelly R. Ruppert},
  year = {1999},
  doi = {10.3133/ofr99172\_ver1},
  url = {https://pubs.usgs.gov/publication/ofr99172\_ver1},
  note = {Source identifier: ofr99172\_ver1}
}