@misc{indiciaeb39ca6e0a8e0,
  title = {Geologic map of the Tule Springs Quadrangle, San Diego County, California},
  author = {V. R. Todd},
  year = {1982},
  doi = {10.3133/ofr82221},
  url = {https://pubs.usgs.gov/publication/ofr82221},
  note = {Source identifier: ofr82221}
}