@misc{indiciae2112d9e60968,
  title = {Laboratory study of high-grade uranium-bearing lignite from Harding County, South Dakota},
  author = {James M. Schopf and Ralph J. Gray},
  year = {1956},
  doi = {10.3133/tei480},
  url = {https://pubs.usgs.gov/publication/tei480},
  note = {Source identifier: tei480}
}