@misc{indiciae326002d43156,
  title = {Geologic map of the Grayback quadrangle, Pinal County, Arizona},
  author = {Henry Rowland Cornwall and Medora Louise Hooper Krieger},
  year = {1975},
  doi = {10.3133/gq1206},
  url = {https://pubs.usgs.gov/publication/gq1206},
  note = {Source identifier: gq1206}
}