@misc{indiciaecdf8e88fc2d5,
  title = {Geology and petroleum resources of the De Beque oil field, Colorado},
  author = {E. G. Woodruff},
  year = {1913},
  doi = {10.3133/b531c},
  url = {https://pubs.usgs.gov/publication/b531C},
  note = {Source identifier: b531C}
}