@misc{indiciae7161b6edb314,
  title = {Challenging questions for geology and geophysics in the 21st century},
  author = {Bruce R. Doe},
  year = {1992},
  doi = {10.3133/ofr92515},
  url = {https://pubs.usgs.gov/publication/ofr92515},
  note = {Source identifier: ofr92515}
}