@misc{indiciae390680a02259,
  title = {Potentiometric surface of the middle Potomac Aquifer in Virginia, 1993},
  author = {E. C. Hammond and E. R. McFarland and M. J. Focazio},
  year = {1994},
  doi = {10.3133/ofr94372},
  url = {https://pubs.usgs.gov/publication/ofr94372},
  note = {Source identifier: ofr94372}
}