@misc{indiciaeb02a1a61f76c,
  title = {Earth science photographs from the U.S. Geological Survey Library},
  author = {Joseph K. McGregor and Carl C. Abston},
  year = {1995},
  doi = {10.3133/ds21},
  url = {https://pubs.usgs.gov/publication/ds21},
  note = {Source identifier: ds21}
}