@misc{indiciae9d1655b048f1,
  title = {Geologic map of the East of Grotto Hills Quadrangle, California},
  author = {J. E. Nielson},
  year = {1998},
  doi = {10.3133/ofr98469},
  url = {https://pubs.usgs.gov/publication/ofr98469},
  note = {Source identifier: ofr98469}
}