@misc{indiciaeb6782e9cdacd,
  title = {Dike rocks of the Apishapa quadrangle, Colorado},
  author = {Whitman Cross},
  year = {1915},
  doi = {10.3133/pp90c},
  url = {https://pubs.usgs.gov/publication/pp90C},
  note = {Source identifier: pp90C}
}