@misc{indiciae641bfeaf973c,
  title = {Radioactivity of asphaltites, coals, and shales in Tennessee, Kentucky, West Virginia, and Pennsylvania},
  author = {John Marshall Nelson},
  year = {1948},
  doi = {10.3133/tei43},
  url = {https://pubs.usgs.gov/publication/tei43},
  note = {Source identifier: tei43}
}