@misc{indiciaecc2522e05fc3,
  title = {Map of geologic sources of radioactivity in the United States},
  author = {Mary E. Strobell and Helen L. Cannon},
  year = {1975},
  doi = {10.3133/ofr75270},
  url = {https://pubs.usgs.gov/publication/ofr75270},
  note = {Source identifier: ofr75270}
}