@misc{indiciae544a5233e96c,
  title = {Geology of the Greenwood quadrangle, Arkansas-Oklahoma},
  author = {B.R. Haley and T. A. Hendricks},
  year = {1968},
  doi = {10.3133/pp536a},
  url = {https://pubs.usgs.gov/publication/pp536A},
  note = {Source identifier: pp536A}
}