@misc{indiciae2aeebaebdf2a,
  title = {The Generalized Legendre-Clebsch Condition on state/control constrained arcs},
  author = {Seywald, Hans and Cliff, Eugene M.},
  year = {1993},
  url = {https://ntrs.nasa.gov/citations/19930067345},
  note = {Source identifier: 19930067345}
}