@misc{indiciae0b91e1cffa1e,
  title = {Plan of study for the northern Great Plains regional aquifer-system analysis in parts of Montana, North Dakota, South Dakota, and Wyoming},
  author = {George A. Dinwiddie},
  year = {1979},
  doi = {10.3133/wri7934},
  url = {https://pubs.usgs.gov/publication/wri7934},
  note = {Source identifier: wri7934}
}