@misc{indiciaec72d10d12feb,
  title = {Preliminary geologic map of the Sahuarita quadrangle, Pima County, Arizona},
  author = {Harald Drewes},
  year = {1968},
  doi = {10.3133/ofr6889},
  url = {https://pubs.usgs.gov/publication/ofr6889},
  note = {Source identifier: ofr6889}
}