@misc{indiciae4d7788acf2f1,
  title = {The James River-Roanoke River manganese district, Virginia},
  author = {G.H. Espenshade},
  year = {1944},
  doi = {10.3133/ofr4462},
  url = {https://pubs.usgs.gov/publication/ofr4462},
  note = {Source identifier: ofr4462}
}