@misc{indiciae71e8104b5d74,
  title = {Geologic map of science study area 1B, west Mangala Valles region of Mars},
  author = {M. G. Chapman and Harold Masursky and A. L. Dial},
  year = {1991},
  doi = {10.3133/i2087},
  url = {https://pubs.usgs.gov/publication/i2087},
  note = {Source identifier: i2087}
}