@misc{indiciaec1e90208286e,
  title = {Distribution of the basal clastic unit of the Oligocene Chadron Formation in the alliance 2-degree Quadrangle, northwestern Nebraska},
  author = {K. A. Dickinson},
  year = {1990},
  doi = {10.3133/ofr90416},
  url = {https://pubs.usgs.gov/publication/ofr90416},
  note = {Source identifier: ofr90416}
}