@misc{indiciaeac4c4382ae8f,
  title = {Colorado's ancient bristlecone pines},
  author = {F.C. Brunstein},
  year = {1993},
  doi = {10.3133/ofr93250},
  url = {https://pubs.usgs.gov/publication/ofr93250},
  note = {Source identifier: ofr93250}
}