@misc{indiciaedd593d9c62e3,
  title = {The digital coal map of South America in ARC/INFO format},
  author = {Laura R. Biewick and Jean N. Weaver},
  year = {1995},
  doi = {10.3133/ofr95235},
  url = {https://pubs.usgs.gov/publication/ofr95235},
  note = {Source identifier: ofr95235}
}