@misc{indiciaecf37072a4dff,
  title = {Bedrock map of Fairfax County, Virginia},
  author = {Avery A. Drake and A.J. Froelich},
  year = {1977},
  doi = {10.3133/ofr77523},
  url = {https://pubs.usgs.gov/publication/ofr77523},
  note = {Source identifier: ofr77523}
}