@misc{indiciaeed33f02c89f8,
  title = {Interplanetary guidance system requirements study. Volume 2 - Computer program descriptions. Part 1 - Program descriptions for interplanetary free-fall trajectories},
  year = {1967},
  url = {https://ntrs.nasa.gov/citations/19680002373},
  note = {Source identifier: 19680002373}
}