@misc{indiciae2970fd9354dc, 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}, year = {1992}, doi = {10.3133/b1839k\_1992}, url = {https://pubs.usgs.gov/publication/b1839K\_1992}, note = {Source identifier: b1839K\_1992} }