@misc{indiciaebb3dbd3bbfe2,
  title = {Index maps showing available topography and aerial photography for Craig 1° x 2° quadrangle, Colorado and Wyoming},
  author = {Irving Jerome Witkind and J. W. Keogh and J. R. Grocock},
  year = {1975},
  doi = {10.3133/ofr7542},
  url = {https://pubs.usgs.gov/publication/ofr7542},
  note = {Source identifier: ofr7542}
}