@misc{indiciae5d24c4ec314c,
  title = {Geology of part of the northern Virginia Piedmont},
  author = {Louis Pavlides},
  year = {1990},
  doi = {10.3133/ofr90548},
  url = {https://pubs.usgs.gov/publication/ofr90548},
  note = {Source identifier: ofr90548}
}