@misc{indiciaed7d374e42390,
  title = {Composition, clay mineralogy, and diagenesis of the Simpson Group (Middle Ordovician), Grady County, Oklahoma},
  author = {Richard M. Pollastro},
  year = {1991},
  doi = {10.3133/b1866h},
  url = {https://pubs.usgs.gov/publication/b1866H},
  note = {Source identifier: b1866H}
}