@misc{indiciae2999126d8a2d,
  title = {Aeromagnetic map of the Bopolu quadrangle, Liberia},
  author = {John Charles Behrendt and Cletus B. Wotorson},
  year = {1971},
  doi = {10.3133/ofr7120},
  url = {https://pubs.usgs.gov/publication/ofr7120},
  note = {Source identifier: ofr7120}
}