@article{196051,
      note = {Distributed to depository libraries in microfiche.},
      author = {Burkhardt, M. R.},
      url = {http://library.usi.edu/record/196051},
      title = {Methods of analysis by the U.S. Geological Survey National  Water Quality Laboratory determination of methylene blue  active substances by spectrophotometry / [microform] :},
      publisher = {U.S. Dept. of the Interior, U.S. Geological Survey :},
      recid = {196051},
      pages = {1 v.},
      address = {Denver, Colo. :},
      year = {1995},
}