@misc{indiciae8656188a8c42,
  title = {Overview of Mars transportation options and issues},
  author = {Adams, Alan and Priest, C. C. and Sumrall, Phil and Woodcock, Gordon},
  year = {1990},
  url = {https://ntrs.nasa.gov/citations/19910025532},
  note = {Source identifier: 19910025532}
}