@misc{indiciae9ce42292b1cd,
  title = {The difference between the potentiometric surfaces of the Aquia Aquifer of September 1986 and September 1988 in southern Maryland},
  author = {Frederick K. Mack and David C. Andreasen and Stephen E. Curtin and Judith C. Wheeler},
  year = {1990},
  doi = {10.3133/wri904039},
  url = {https://pubs.usgs.gov/publication/wri904039},
  note = {Source identifier: wri904039}
}