@misc{indiciae0fff6c38947a,
  title = {Structure contour map of the Avella and part of the Steubenville East quadrangles, Washington County, Pennsylvania},
  author = {Stanley P. Schweinfurth},
  year = {1972},
  doi = {10.3133/ofr72341},
  url = {https://pubs.usgs.gov/publication/ofr72341},
  note = {Source identifier: ofr72341}
}