@misc{indiciaec4fac93bfef3,
  title = {Potentiometric surface of the Aquia Aquifer in southern Maryland, September 1990},
  author = {Frederick K. Mack and S. E. Curtin and D. C. Andreasen and J. C. Wheeler},
  year = {1992},
  doi = {10.3133/ofr92459},
  url = {https://pubs.usgs.gov/publication/ofr92459},
  note = {Source identifier: ofr92459}
}