@misc{indiciaeb2d0cdf8ad90,
  title = {Gravity survey in the San Luis Valley area, Colorado},
  author = {J. Robert Gaca and Daniel E. Karig},
  year = {1965},
  doi = {10.3133/ofr6646},
  url = {https://pubs.usgs.gov/publication/ofr6646},
  note = {Source identifier: ofr6646}
}