@misc{indiciae7ac266427715,
  title = {Geographic map of the Zorzor Quadrangle, Liberia},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey and Liberian Geological Survey},
  year = {1972},
  doi = {10.3133/i773a},
  url = {https://pubs.usgs.gov/publication/i773A},
  note = {Source identifier: i773A}
}