@misc{indiciaeb507f7041de7,
  title = {Circum-Arctic map of permafrost and ground-ice conditions},
  author = {J. Brown and O. J. Ferrians and J. A. Heginbottom and E. S. Melnikov},
  year = {1997},
  doi = {10.3133/cp45},
  url = {https://pubs.usgs.gov/publication/cp45},
  note = {Source identifier: cp45}
}