@misc{indiciae14f11fcb3cfb,
  title = {Comparative geochemistry of Devonian shale cores from the Appalachian Basin, Mason, Monongalia, and Upshur counties, West Virginia; Illinois Basin, Tazwell County, Illinois, and Clark County, Indiana; and Michigan Basin, Sanilac County, Michigan},
  author = {Joel S. Leventhal},
  year = {1980},
  doi = {10.3133/ofr80938},
  url = {https://pubs.usgs.gov/publication/ofr80938},
  note = {Source identifier: ofr80938}
}