@misc{indiciaec20366983dee,
  title = {Structure contour map of the surface rocks of the Model anticline, Las Animas County, Colorado},
  author = {N. W. Bass and C.E. Straub and H.O. Woodbury},
  year = {1947},
  doi = {10.3133/om68},
  url = {https://pubs.usgs.gov/publication/om68},
  note = {Source identifier: om68}
}