@misc{indiciae1123601a8c26,
  title = {Profiles of gamma-ray and magnetic data from aerial surveys over the conterminous United States},
  author = {Joseph S. Duval and Frederic E. Riggle},
  year = {1999},
  doi = {10.3133/ds31},
  url = {https://pubs.usgs.gov/publication/ds31},
  note = {Source identifier: ds31}
}