@misc{indiciaec8ad83a6ee31,
  title = {Aerial gamma-ray surveys of the conterminous United States and Alaska},
  author = {Joseph S. Duval},
  year = {1999},
  doi = {10.3133/ofr99562l},
  url = {https://pubs.usgs.gov/publication/ofr99562L},
  note = {Source identifier: ofr99562L}
}