@misc{indiciae6b7c397bc090,
  title = {Map of assessed shale gas in the United States, 2012},
  author = {U.S. Geological Survey National Assessment of Oil and Gas Resources Team and Laura R. H. Biewick},
  year = {2013},
  doi = {10.3133/ds69z},
  url = {https://pubs.usgs.gov/publication/ds69Z},
  note = {Source identifier: ds69Z}
}