@misc{indiciae760e1347a649,
  title = {Coal and coalbed-methane resources in the Appalachian and Black Warrior basins: maps showing the distribution of coal fields, coal beds, and coalbed-methane fields},
  author = {Michael H. Trippi and Leslie F. Ruppert and Robert C. Milici and Scott A. Kinney},
  year = {2014},
  doi = {10.3133/pp1708d.1},
  url = {https://pubs.usgs.gov/publication/pp1708D.1},
  note = {Source identifier: pp1708D.1}
}