@misc{indiciae36357bd78637,
  title = {Coalification of organic matter in coal balls of the Pennsylvanian (upper Carboniferous) of the Illinois Basin, United States},
  author = {Paul C. Lyons and Carolyn L. Thompson and Patrick G. Hatcher and F. W. Brown and M.A. Millay and Nikolaus Szeverenyi and G.E. Maciel},
  year = {1984},
  doi = {10.1016/0146-6380(84)90010-x},
  url = {https://pubs.usgs.gov/publication/70013850},
  note = {Source identifier: 70013850}
}