@misc{indiciaec85bfe155ed7,
  title = {High speed turboprop aeroacoustic study (counterrotation). Volume 2: Computer programs},
  author = {Whitfield, C. E. and Mani, R. and Gliebe, P. R.},
  year = {1990},
  url = {https://ntrs.nasa.gov/citations/19920022004},
  note = {Source identifier: 19920022004}
}