@misc{indiciae3e36f2747053,
  title = {Volcanic versus anthropogenic carbon dioxide},
  author = {T. Gerlach},
  year = {2011},
  doi = {10.1029/2011eo240001},
  url = {https://pubs.usgs.gov/publication/70036496},
  note = {Source identifier: 70036496}
}