@misc{indiciae85c9784805aa,
  title = {A summary of the U.S. Geological Survey National Water-Quality Assessment program},
  author = {R.M. Hirsch and W.M. Alley and W. G. Wilber},
  year = {1988},
  doi = {10.3133/ofr8895},
  url = {https://pubs.usgs.gov/publication/ofr8895},
  note = {Source identifier: ofr8895}
}