@article{233396,
      recid = {233396},
      author = {Curtin, Stephen E. and Andreasen, David C. and Mack,  Frederick K.},
      title = {The difference between the potentiometric surfaces of the  upper Patapsco Aquifer, September 1990 and September 1997  in Southern Maryland [microform] /},
      publisher = {U.S. Geological Survey ;},
      address = {Baltimore, Md. :},
      pages = {1 map :},
      year = {1999},
      note = {Blackline print.},
      url = {http://library.usi.edu/record/233396},
}