@misc{indiciaedceea7af746b,
  title = {Preliminary synthesis of subsurface stratigraphy of the Niobrara Formation (Upper Cretaceous) in the Northern Great Plains},
  author = {George W. Shurr and Jayne L. Sieverding},
  year = {1980},
  doi = {10.3133/ofr801266},
  url = {https://pubs.usgs.gov/publication/ofr801266},
  note = {Source identifier: ofr801266}
}