@misc{indiciae58660afcf52c,
  title = {PROJECTS FOR EARLY MANNED INTERPLANETARY FLIGHT},
  author = {Gillespie, R. W. and Ragsac, R. V. and Ross, S.},
  year = {1963},
  url = {https://ntrs.nasa.gov/citations/19630003024},
  note = {Source identifier: 19630003024}
}