@misc{indiciae67ed375cdfa7,
  title = {Preliminary mineral resource assessment of the Tucson and Nogales 1° by 2° quadrangles, Arizona},
  year = {1990},
  doi = {10.3133/ofr90276},
  url = {https://pubs.usgs.gov/publication/ofr90276},
  note = {Source identifier: ofr90276}
}