@misc{indiciae6e8a16deb8f9,
  title = {Map showing wells drilled for oil and gas deeper than 20,000 feet in the conterminous United States and offshore},
  author = {K. I. comiled by Takahashi and K. I. Cunningham},
  year = {1987},
  doi = {10.3133/om220},
  url = {https://pubs.usgs.gov/publication/om220},
  note = {Source identifier: om220}
}