@misc{indiciaec44a31b76d91,
  title = {Manned space flight - present and future steps},
  author = {Gilruth, R. R. and Strass, H. K.},
  year = {1960},
  url = {https://ntrs.nasa.gov/citations/19640057264},
  note = {Source identifier: 19640057264}
}