@misc{indiciae9d0f1e1d2deb,
  title = {Ground-water age and flow at the Great Sand Dunes National Monument, south-central Colorado},
  author = {Michael G. Rupert and Niel Plummer},
  year = {2004},
  doi = {10.3133/fs20043051},
  url = {https://pubs.usgs.gov/publication/fs20043051},
  note = {Source identifier: fs20043051}
}