@misc{indiciae6e05c6389154,
  title = {Constrained low-thrust guidance.},
  author = {Ungs, M. J. and Kornhauser, A. L. and Lion, P. M.},
  year = {1973},
  url = {https://ntrs.nasa.gov/citations/19730032115},
  note = {Source identifier: 19730032115}
}