@misc{indiciae11f44f307c86,
  title = {Helicopter trajectory planning using optimal control theory},
  author = {Menon, P. K. A. and Cheng, V. H. L. and Kim, E.},
  year = {1988},
  url = {https://ntrs.nasa.gov/citations/19880067344},
  note = {Source identifier: 19880067344}
}