@misc{indiciaee4989aeea2b8,
  title = {Five-day mission plan to investigate the geology of the Marius Hills region of the Moon},
  author = {Donald Parker Elston and Charles R. Willingham},
  year = {1969},
  doi = {10.3133/ofr6991},
  url = {https://pubs.usgs.gov/publication/ofr6991},
  note = {Source identifier: ofr6991}
}