@misc{indiciae37424c7a8b6d,
  title = {Geologic map of the Tucson and Nogales quadrangles (Arizona, scale 1:250,000): A digital database},
  author = {J.A. Peterson and J. R. Berquist and S. J. Reynolds and S. S. Page-Nedell and Gustav P. Oland and Douglas M. Hirschberg},
  year = {2001},
  doi = {10.3133/ofr01275},
  url = {https://pubs.usgs.gov/publication/ofr01275},
  note = {Source identifier: ofr01275}
}