@misc{indiciae2a1257783427,
  title = {Cost estimation for unmanned lunar and planetary programs},
  author = {Dunkin, J. H. and Pekar, P. R. and Spadoni, D. J. and Stone, C. A.},
  year = {1973},
  url = {https://ntrs.nasa.gov/citations/19730015113},
  note = {Source identifier: 19730015113}
}