@misc{indiciae91e63e837539,
  title = {Gravity and aeromagnetic anomaly maps of the Ajo and Lukeville 1° x 2° quadrangles, southwestern Arizona},
  author = {D. P. Klein and R.P. Kucks},
  year = {1991},
  doi = {10.3133/i2139},
  url = {https://pubs.usgs.gov/publication/i2139},
  note = {Source identifier: i2139}
}