@misc{indiciae37b069d1ba7c,
  title = {Stratigraphic framework of Cambrian and Ordovician rocks in the central Appalachian Basin from Medina County, Ohio, through southwestern and south-central Pennsylvania to Hampshire County, West Virginia},
  author = {Robert T. Ryder and Anita G. Harris and John E. Repetski and Robert D. revised and digitized by Crangle},
  year = {2003},
  doi = {10.3133/b1839k},
  url = {https://pubs.usgs.gov/publication/b1839K},
  note = {Source identifier: b1839K}
}