@misc{indiciaec35ab21788e9,
  title = {A method for determining the characteristic functions associated with the aeroelastic instabilities of helicopter rotors in forward flight},
  author = {Piarulli, V. J. and White, R. P., Jr.},
  year = {1970},
  url = {https://ntrs.nasa.gov/citations/19700020850},
  note = {Source identifier: 19700020850}
}