@misc{indiciaef1d1ff38a27a,
  title = {Preliminary geologic map of the Pinal Ranch quadrangle, Arizona},
  author = {N. P. Peterson},
  year = {1961},
  doi = {10.3133/mf81},
  url = {https://pubs.usgs.gov/publication/mf81},
  note = {Source identifier: mf81}
}