@misc{indiciae8d66fc939336,
  title = {Preliminary stratigraphic cross section showing radioactive zones in the Devonian black shales of the central part of the Appalachian basin},
  author = {John B. Roen and L.G. Wallace and Wallace De Witt},
  year = {1977},
  doi = {10.3133/ofr77841},
  url = {https://pubs.usgs.gov/publication/ofr77841},
  note = {Source identifier: ofr77841}
}