@article{219556,
      recid = {219556},
      author = {Antweiler, Ronald C. and Patton, Charles J. and Taylor,  Howard E.},
      title = {Automated, colorimetric methods for determination of  nitrate plus nitrite, nitrite, ammonium and orthophosphate  ions in natural water samples [microform] /},
      publisher = {U.S. Geological Survey :},
      address = {Denver, Colo. :},
      pages = {iv, 23 leaves :},
      year = {1996},
      url = {http://library.usi.edu/record/219556},
}