@misc{indiciaee43ba6cb4671,
  title = {Geographic map of the Harper Quadrangle, Liberia},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey and Liberian Geological Survey},
  year = {1973},
  doi = {10.3133/i780a},
  url = {https://pubs.usgs.gov/publication/i780A},
  note = {Source identifier: i780A}
}