@misc{indiciae141bc6b209c8,
  title = {Grain-size analyses of Ordovician sandstones from the Midwestern states},
  author = {Keith Brindley Ketner},
  year = {1979},
  doi = {10.3133/ofr79230},
  url = {https://pubs.usgs.gov/publication/ofr79230},
  note = {Source identifier: ofr79230}
}