@misc{indiciaef9aa6cdaf2a5,
  title = {Preliminary geologic map of the Shadow Mountains quadrangle, Los Angeles and San Bernardino Counties, California},
  author = {T. W. Dibblee},
  year = {1960},
  doi = {10.3133/mf227},
  url = {https://pubs.usgs.gov/publication/mf227},
  note = {Source identifier: mf227}
}