@misc{indiciaea6d7a100b938,
  title = {Technology requirements for advanced earth-orbital transportation systems},
  author = {Haefeli, R. C. and Littler, E. G. and Hurley, J. B. and Winter, M. G.},
  year = {1977},
  url = {https://ntrs.nasa.gov/citations/19780003243},
  note = {Source identifier: 19780003243}
}