@misc{indiciae003534e91722,
  title = {External quality-assurance results for the National Atmospheric Deposition Program/National Trends Network, 1995-96},
  author = {John D. Gordon},
  year = {1999},
  doi = {10.3133/wri994072},
  url = {https://pubs.usgs.gov/publication/wri994072},
  note = {Source identifier: wri994072}
}