@misc{indiciaeb59e0b339b06,
  title = {Mission analysis for interplanetary vehicles with solar electric propulsion.},
  author = {Barber, T. A. and Flandro, G. A.},
  year = {1967},
  url = {https://ntrs.nasa.gov/citations/19670060006},
  note = {Source identifier: 19670060006}
}