@misc{indiciae5e766a83278e,
  title = {Geologic map of the Fredericksburg 30' x 60' quadrangle, Virginia and Maryland},
  author = {R. B. Mixon and Louis Pavlides and David S. Powars and A.J. Froelich and Robert E. Weems and J. Stephen Schindler and Wayne L. Newell and Lucy E. Edwards and L. W. Ward},
  year = {2000},
  doi = {10.3133/i2607},
  url = {https://pubs.usgs.gov/publication/i2607},
  note = {Source identifier: i2607}
}