@misc{indiciaebda3e6f71b3f,
  title = {Niobium (columbium) and tantalum resources of Brazil},
  author = {Max Gregg White},
  year = {1975},
  doi = {10.3133/ofr7529},
  url = {https://pubs.usgs.gov/publication/ofr7529},
  note = {Source identifier: ofr7529}
}