@misc{indiciaec4c8105ec045,
  title = {Shaded relief map of Mars},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1975},
  doi = {10.3133/i940},
  url = {https://pubs.usgs.gov/publication/i940},
  note = {Source identifier: i940}
}