@misc{indiciaecf07382e0255,
  title = {Fractionation and characterization of natural organic matter from certain rivers and soils by free-flow electrophoresis},
  author = {J.A. Leenheer and Ronald L. Malcolm},
  year = {1973},
  doi = {10.3133/wsp1817e},
  url = {https://pubs.usgs.gov/publication/wsp1817E},
  note = {Source identifier: wsp1817E}
}