@misc{indiciae5f98d2b8c4d1,
  title = {Petrography and geochemistry of the San Miguel lignite, Jackson Group (Eocene), south Texas},
  author = {Peter D. Warwick and Sharon S. Crowley and Leslie F. Ruppert and James Pontolillo},
  year = {1996},
  doi = {10.1016/0146-6380(96)00018-6},
  url = {https://pubs.usgs.gov/publication/70019352},
  note = {Source identifier: 70019352}
}