@misc{indiciaee1236184fd2e,
  title = {Shuttle evolution - Improved aft propulsion system},
  author = {Karakulko, Witalij and Frazier, Scott R.},
  year = {1991},
  url = {https://ntrs.nasa.gov/citations/19910058012},
  note = {Source identifier: 19910058012}
}