@misc{indiciae77aa0541071b,
  title = {External quality-assurance results for the National Atmospheric Deposition Program/National Trends Network during 1994},
  author = {J.D. Gordon and M.A. Nilles and D.K. Polascek and M.E. Ratcliff},
  year = {1997},
  doi = {10.3133/wri974201},
  url = {https://pubs.usgs.gov/publication/wri974201},
  note = {Source identifier: wri974201}
}