@misc{indiciae682e59cbcd03,
  title = {The difference between the potentiometric surfaces of the upper Patapsco aquifer, September 1990 and September 1999 in southern Maryland},
  author = {Stephen E. Curtin and David C. Andreasen and Judith C. Wheeler},
  year = {2003},
  doi = {10.3133/ofr01209},
  url = {https://pubs.usgs.gov/publication/ofr01209},
  note = {Source identifier: ofr01209}
}