@misc{indiciaec9ab5358efcc,
  title = {Geologic map of the Parker Quadrangle, Arapahoe and Douglas counties, Colorado},
  author = {John O. Mayberry and Robert M. Lindvall},
  year = {1972},
  doi = {10.3133/i770a},
  url = {https://pubs.usgs.gov/publication/i770A},
  note = {Source identifier: i770A}
}