@misc{indiciaef843924ea1cb,
  title = {Sun-earth libration point trajectories that avoid the solar exclusion zone},
  author = {Howell, K. C. and Pernicka, H. J.},
  year = {1990},
  url = {https://ntrs.nasa.gov/citations/19910025778},
  note = {Source identifier: 19910025778}
}