@article{198861,
      note = {Distributed to depository libraries in microfiche.},
      author = {Mack, Frederick K.},
      url = {http://library.usi.edu/record/198861},
      title = {The difference between the potentiometric surfaces of the  Aquia Aquifer of September 1982 and September 1990 in  southern Maryland [microform] /},
      publisher = {The Survey ;},
      recid = {198861},
      pages = {1 map ;},
      address = {Towson, Md. :},
      year = {1992},
}