@misc{indiciae03e42c86efe8,
  title = {Digital elevation models for Slumgullion landslide, Hinsdale County, Colorado based on 1985 and 1990 aerial photography},
  author = {Philip S. Powers and David J. Varnes and William Z. Savage},
  year = {1992},
  doi = {10.3133/ofr92535b},
  url = {https://pubs.usgs.gov/publication/ofr92535B},
  note = {Source identifier: ofr92535B}
}