@misc{indiciaefcb3f48b3ecd,
  title = {A method for nitrate collection for δ 15 N and δ 18 O analysis from waters with low nitrate concentrations},
  author = {Cecily C.Y. Chang and J. Langston and M. Riggs and K. Campbell and S. R. Silva and C. Kendall},
  year = {1999},
  doi = {10.1139/f99-126},
  url = {https://pubs.usgs.gov/publication/70021670},
  note = {Source identifier: 70021670}
}