@misc{indiciaecd2f3d4ce17f,
  title = {The difference between the potentiometric surfaces of the Upper Patapsco aquifer in southern Maryland, September 1990 and September 2009},
  author = {Stephen E. Curtin and David C. Andreasen and Andrew W. Staley},
  year = {2010},
  doi = {10.3133/ofr20101206},
  url = {https://pubs.usgs.gov/publication/ofr20101206},
  note = {Source identifier: ofr20101206}
}