@misc{indiciae0972c3512934,
  title = {Preliminary geologic map of the Figure Four Spring quadrangle, Rio Blanco and Garfield Counties, Colorado},
  author = {R. C. Johnson},
  year = {1977},
  doi = {10.3133/mf912},
  url = {https://pubs.usgs.gov/publication/mf912},
  note = {Source identifier: mf912}
}