@misc{indiciaecc7790984630,
  title = {Geologic map of the Mount Wrightson Quadrangle, southeast of Tucson, Santa Cruz, and Pima counties, Arizona},
  author = {Harald Drewes},
  year = {1971},
  doi = {10.3133/i614},
  url = {https://pubs.usgs.gov/publication/i614},
  note = {Source identifier: i614}
}