@misc{indiciae4b92b3a5ee30,
  title = {Economics and coal resource appraisal: strippable coal in the Illinois Basin ( USA)},
  author = {E. D. Attanasi and E.K. Green},
  year = {1981},
  url = {https://pubs.usgs.gov/publication/70011865},
  note = {Source identifier: 70011865}
}