@misc{indiciae64d64729af99,
  title = {Stability of nitrate-ion concentrations in simulated deposition samples used for quality-assurance activities by the U.S. Geological Survey},
  author = {T. C. Willoughby and R.B. See and L.J. Schroder},
  year = {1989},
  doi = {10.3133/wri894042},
  url = {https://pubs.usgs.gov/publication/wri894042},
  note = {Source identifier: wri894042}
}