@misc{indiciaea5ef68bf6163,
  title = {General and engineering geology of the United States Air Force Academy site, Colorado, with a section on ground water},
  author = {David J. Varnes and Glenn R. Scott and W. D. E. Cardwell and E. D. Jenkins},
  year = {1967},
  doi = {10.3133/pp551},
  url = {https://pubs.usgs.gov/publication/pp551},
  note = {Source identifier: pp551}
}