@misc{indiciaeec1016a1822b,
  title = {Concepts for Variable/Multi-Speed Rotorcraft Drive System},
  author = {Stevens, Mark A. and Handschuh, Robert F. and Lewicki, David G.},
  year = {2008},
  url = {https://ntrs.nasa.gov/citations/20080045530},
  note = {Source identifier: 20080045530}
}