@misc{indiciaed54340279a71,
  title = {Map showing contours on the base of saprolite, Fairfax County, Virginia},
  author = {A.J. Froelich and T.L. Heironimus},
  year = {1977},
  doi = {10.3133/ofr77710},
  url = {https://pubs.usgs.gov/publication/ofr77710},
  note = {Source identifier: ofr77710}
}