@misc{indiciae19674dbeb2e9,
  title = {The difference between the potentiometric surfaces of the Aquia Aquifer of September 1982 and September 1990 in southern Maryland},
  author = {Frederick K. Mack and S. E. Curtin and D. C. Andreasen and J. C. Wheeler},
  year = {1992},
  doi = {10.3133/ofr92463},
  url = {https://pubs.usgs.gov/publication/ofr92463},
  note = {Source identifier: ofr92463}
}