@misc{indiciaec8d7adbc736c,
  title = {Bouguer gravity map of Colorado},
  author = {John C. Behrendt and LaCretia Y. Bajwa},
  year = {1972},
  doi = {10.3133/ofr7231},
  url = {https://pubs.usgs.gov/publication/ofr7231},
  note = {Source identifier: ofr7231}
}