@misc{indiciaea9e0554fdc92,
  title = {A Variational Method for the Optimization of Interplanetary Round-Trip Trajectories},
  author = {MacKay, John S. and Rossa, Leonard G.},
  year = {1963},
  url = {https://ntrs.nasa.gov/citations/19630003917},
  note = {Source identifier: 19630003917}
}