@misc{indiciae117d40e6759a,
  title = {Thickness of Upper Cretaceous rocks from the top of the Niobrara Formation to the base of the Fox Hills Sandstone, Powder River basin, Wyoming and Montana},
  author = {J. E. Fox and Debra K. Higley},
  year = {1987},
  doi = {10.3133/ofr87340a},
  url = {https://pubs.usgs.gov/publication/ofr87340A},
  note = {Source identifier: ofr87340A}
}