@misc{indiciae29b103a34eec,
  title = {Preliminary geologic map of the Middletown quadrangle, Frederick and Shenandoah Counties, Virginia},
  author = {Randall C. Orndorff and Jack Burton Epstein and R. C. McDowell},
  year = {1993},
  doi = {10.3133/ofr9324},
  url = {https://pubs.usgs.gov/publication/ofr9324},
  note = {Source identifier: ofr9324}
}