@misc{indiciae2bba9ea36388,
  title = {Geologic map of the Middletown quadrangle, Frederick, Shenandoah, and Warren Counties, Virginia},
  author = {Randall C. Orndorff and Jack Burton Epstein and Robert C. McDowell},
  year = {1999},
  doi = {10.3133/gq1803},
  url = {https://pubs.usgs.gov/publication/gq1803},
  note = {Source identifier: gq1803}
}