@misc{indiciae114806bc021b,
  title = {Geologic map of the Avella quadrangle and part of the Steubenville East Quadrangle, Washington County, Pennsylvania},
  author = {S. P. Schweinfurth},
  year = {1976},
  doi = {10.3133/i908},
  url = {https://pubs.usgs.gov/publication/i908},
  note = {Source identifier: i908}
}