@misc{indiciae2b1ca3f1c1fa,
  title = {Upper Cretaceous bituminous coal deposits of the Olmos Formation, Maverick County, Texas},
  author = {Robert W. Hook and Peter D. Warwick and John R. SanFilipo},
  year = {2011},
  url = {https://pubs.usgs.gov/publication/70192705},
  note = {Source identifier: 70192705}
}