@misc{indiciae49a7f23ac1bb,
  title = {Geology and mineral deposits of the James River-Roanoke River manganese district, Virginia},
  author = {Gilbert H. Espenshade},
  year = {1954},
  doi = {10.3133/b1008},
  url = {https://pubs.usgs.gov/publication/b1008},
  note = {Source identifier: b1008}
}