@misc{indiciae4a630a9beb01,
  title = {Total-count gamma radiation map of the Harper Quadrangle, Liberia},
  author = {John C. Behrendt and C.S. Wotorson},
  year = {1974},
  doi = {10.3133/i780c},
  url = {https://pubs.usgs.gov/publication/i780C},
  note = {Source identifier: i780C}
}