@misc{indiciae94601646fa1c,
  title = {Preliminary map of manganese provinces in the conterminous United States},
  author = {Edwin Wilson Tooker and William F. Cannon},
  year = {1980},
  doi = {10.3133/ofr79576o},
  url = {https://pubs.usgs.gov/publication/ofr79576O},
  note = {Source identifier: ofr79576O}
}