@misc{indiciae5ab55cf70709,
  title = {Maps of northeastern Oklahoma and parts of adjacent states showing the thickness and subsurface distribution of Lower Ordovician and Upper Cambrian rocks below the Simpson group},
  author = {H.A. Ireland and John H. Warren},
  year = {1946},
  doi = {10.3133/om52},
  url = {https://pubs.usgs.gov/publication/om52},
  note = {Source identifier: om52}
}