@misc{indiciaee77e20ddec71,
  title = {External quality-assurance results for the National Atmospheric Deposition Program/National Trends Network, 1997-99},
  author = {John D. Gordon and Natalie E. Latysh and Sandy J. Lindholm},
  year = {2003},
  doi = {10.3133/wri034027},
  url = {https://pubs.usgs.gov/publication/wri034027},
  note = {Source identifier: wri034027}
}