@misc{indiciae1f7ff9cff3a9,
  title = {Unmanned spacecraft RTG shield optimization study Midterm report},
  author = {Huang, R. and Steyn, J. J.},
  year = {1969},
  url = {https://ntrs.nasa.gov/citations/19700009987},
  note = {Source identifier: 19700009987}
}