@misc{indiciaebf9834dbea01,
  title = {Map showing construction materials resources in the Parker quadrangle, Arapahoe and Douglas Counties, Colorado},
  author = {J. O. Maberry},
  year = {1973},
  doi = {10.3133/i770l},
  url = {https://pubs.usgs.gov/publication/i770L},
  note = {Source identifier: i770L}
}