@article{198767,
      note = {Distributed to depository libraries in microfiche.},
      author = {Skipp, Gary. and Brownfield, Isabelle K.},
      url = {http://library.usi.edu/record/198767},
      title = {Improved density gradient separation techniques using  sodium polytungstate and a comparison to the use of other  heavy liquids [microform] /},
      publisher = {U.S. Dept. of the Interior, U.S. Geological Survey :},
      recid = {198767},
      pages = {i, 16 p. :},
      address = {[Denver, Colo.] :},
      year = {1993},
}