@article{196051, recid = {196051}, author = {Burkhardt, M. R.}, 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 :}, address = {Denver, Colo. :}, pages = {1 v.}, year = {1995}, note = {Distributed to depository libraries in microfiche.}, url = {http://library.usi.edu/record/196051}, }