@misc{indiciaefd1ac7bbba79,
  title = {Scientific exploration of comets - A mission study.},
  author = {Giddis, A. R. and Jensen, R. C. and Walton, R. R.},
  year = {1965},
  url = {https://ntrs.nasa.gov/citations/19660036613},
  note = {Source identifier: 19660036613}
}