@misc{indiciaec209b65f887e,
  title = {Preliminary potentiometric-surface map showing fresh-water heads for the Lower Cretaceous rocks in the northern Great Plains of Montana, North Dakota, South Dakota, and Wyoming},
  author = {David H. Lobmeyer},
  year = {1980},
  doi = {10.3133/ofr80757},
  url = {https://pubs.usgs.gov/publication/ofr80757},
  note = {Source identifier: ofr80757}
}