@misc{indiciae433548b92ab4,
  title = {Technology requirements for advanced earth orbital transportation systems. Volume 2: Summary report},
  author = {Hepler, A. K. and Bangsund, E. L.},
  year = {1978},
  url = {https://ntrs.nasa.gov/citations/19780022223},
  note = {Source identifier: 19780022223}
}