@misc{indiciae0d1c4d4f30fa,
  title = {Lunar crater morphology and relative age determination of lunar geologic units - Part 1, Classification; Part 2, Applications},
  author = {Howard A. Pohn and Terry W. Offield},
  year = {1969},
  doi = {10.3133/ofr69209},
  url = {https://pubs.usgs.gov/publication/ofr69209},
  note = {Source identifier: ofr69209}
}