@misc{indiciaecb1614c2c5c8,
  title = {Nitrate-nitrogen concentrations in ground water from three selected areas in Kansas},
  author = {Timothy B. Spruill},
  year = {1982},
  doi = {10.3133/wri8211},
  url = {https://pubs.usgs.gov/publication/wri8211},
  note = {Source identifier: wri8211}
}