@misc{indiciae5b4c2b03ac6e,
  title = {Volcanic rocks of the El Modeno area, Orange County, California},
  author = {R. F. Yerkes},
  year = {1957},
  doi = {10.3133/pp274l},
  url = {https://pubs.usgs.gov/publication/pp274L},
  note = {Source identifier: pp274L}
}