@misc{indiciae184519f78e21,
  title = {Geologic map of the Milligan 15-minute Quadrangle, San Bernadino Coutny, California},
  author = {K. A. Howard and Paul Stone and C. F. Miller},
  year = {1989},
  doi = {10.3133/mf2072},
  url = {https://pubs.usgs.gov/publication/mf2072},
  note = {Source identifier: mf2072}
}