@misc{indiciaeebae4fed225a,
  title = {Geologic map of the SP Mountain quadrangle, Coconino County, Arizona},
  author = {G. E. Ulrich and N. G. Bailey},
  year = {1974},
  doi = {10.3133/ofr745},
  url = {https://pubs.usgs.gov/publication/ofr745},
  note = {Source identifier: ofr745}
}