@misc{indiciae0d11f9b57924,
  title = {Higher order mode propagation in nonuniform circular ducts},
  author = {Cho, Y. C. and Ingard, K. U.},
  year = {1980},
  url = {https://ntrs.nasa.gov/citations/19800014612},
  note = {Source identifier: 19800014612}
}