@misc{indiciaee973b84be7ec,
  title = {Aeromagnetic map of the Hells Gate Roadless Area, Gila County, Arizona},
  author = {R.A. Martin},
  year = {1987},
  doi = {10.3133/mf1644b},
  url = {https://pubs.usgs.gov/publication/mf1644B},
  note = {Source identifier: mf1644B}
}