@misc{indiciaeb31f609cbcd3,
  title = {Geological map of the Gilroy 7.5 minute Quadrangle, California},
  author = {E. J. Helley and J. K. Nakata},
  year = {1991},
  doi = {10.3133/ofr91278},
  url = {https://pubs.usgs.gov/publication/ofr91278},
  note = {Source identifier: ofr91278}
}