@misc{indiciae0b1b4c07cfbb,
  title = {Shaded relief map of the Hellas Quadrangle of Mars},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1979},
  doi = {10.3133/i1169},
  url = {https://pubs.usgs.gov/publication/i1169},
  note = {Source identifier: i1169}
}