@misc{indiciaeef6b6d1f1d43,
  title = {A statistical analysis of the quality of surface water in Nebraska},
  author = {R. A. Engberg},
  year = {1980},
  doi = {10.3133/ofr8043},
  url = {https://pubs.usgs.gov/publication/ofr8043},
  note = {Source identifier: ofr8043}
}