@misc{indiciae35a4dcc1e7db,
  title = {Total-count gamma radiation map of the Zwedru quadrangle, Liberia},
  author = {Cletus S. Wotorson and John Charles Behrendt},
  year = {1971},
  doi = {10.3133/ofr71332},
  url = {https://pubs.usgs.gov/publication/ofr71332},
  note = {Source identifier: ofr71332}
}