@misc{indiciae01755a677d8a,
  title = {Geologic map of the El Cajon Mountain Quadrangle, San Diego County, California},
  author = {Victoria R. Todd},
  year = {1983},
  doi = {10.3133/ofr83781},
  url = {https://pubs.usgs.gov/publication/ofr83781},
  note = {Source identifier: ofr83781}
}