@misc{indiciae19c0869e1b55,
  title = {Aerial gamma-ray surveys of the conterminous United States and Alaska},
  author = {Joseph S. Duval},
  year = {1999},
  doi = {10.3133/ofr99562e},
  url = {https://pubs.usgs.gov/publication/ofr99562E},
  note = {Source identifier: ofr99562E}
}