@misc{indiciaeea6c08094f78,
  title = {Exploration intensity map of the Paleozoic section, Denver Basin, Colorado, Nebraska and Wyoming},
  author = {Debra K. Higley and D. L. Gautier and Richard F. Mast},
  year = {1987},
  doi = {10.3133/ofr87351d},
  url = {https://pubs.usgs.gov/publication/ofr87351D},
  note = {Source identifier: ofr87351D}
}