@misc{indiciaeb3e122160fdd,
  title = {Space Resources and Space Settlements},
  author = {John Billingham and William Gilbreath and Brian O'Leary and Beulah Gossett},
  year = {1977},
  url = {https://ntrs.nasa.gov/citations/19790024054},
  note = {Source identifier: 19790024054}
}