@misc{indiciae9ff939ed7894,
  title = {Geologic Map of the Sif Mons Quadrangle (V-31), Venus},
  author = {Duncan L. Copp and John E. Guest},
  year = {2007},
  doi = {10.3133/sim2898},
  url = {https://pubs.usgs.gov/publication/sim2898},
  note = {Source identifier: sim2898}
}