@misc{indiciaed4775cce9755,
  title = {Aeromagnetic map of the Bopolu Quadrangle, Liberia},
  author = {John C. Behrendt and C.S. Wotorson},
  year = {1974},
  doi = {10.3133/i772b},
  url = {https://pubs.usgs.gov/publication/i772B},
  note = {Source identifier: i772B}
}