@misc{indiciae4a354b5797b3,
  title = {Coal quality loss from acquisition to analysis; a preliminary time study},
  author = {Robert G. Hobbs and James Daniel Cathcart and George A. Correia},
  year = {1983},
  doi = {10.3133/ofr83167},
  url = {https://pubs.usgs.gov/publication/ofr83167},
  note = {Source identifier: ofr83167}
}