@misc{indiciae3dfd6e611cb9,
  title = {Geologic map of the Mare Undarum Quadrangle of the Moon},
  author = {A. B. Olson and D.E. Wilhelms},
  year = {1974},
  doi = {10.3133/i837},
  url = {https://pubs.usgs.gov/publication/i837},
  note = {Source identifier: i837}
}