@misc{indiciaeec5364989f04,
  title = {CoalVal-A coal resource valuation program},
  author = {Timothy J. Rohrbacher and Gary E. McIntosh},
  year = {2010},
  doi = {10.3133/ofr20091282},
  url = {https://pubs.usgs.gov/publication/ofr20091282},
  note = {Source identifier: ofr20091282}
}