@misc{indiciaeab7af1fc80e8,
  title = {Thickness of overburden map of Fairfax County, Virginia},
  author = {A.J. Froelich and T.L. Heironimus},
  year = {1977},
  doi = {10.3133/ofr77797},
  url = {https://pubs.usgs.gov/publication/ofr77797},
  note = {Source identifier: ofr77797}
}