@misc{indiciae186f7a547b2e,
  title = {Geologic studies of deep natural gas resources},
  author = {Vello A. Kuuskraa},
  year = {2001},
  doi = {10.3133/ds67},
  url = {https://pubs.usgs.gov/publication/ds67},
  note = {Source identifier: ds67}
}