@misc{indiciae5a1878d45db3,
  title = {A wave-envelope technique for wave propagation in non-uniform ducts},
  author = {Kaiser, J. E. and Nayfeh, A. H.},
  year = {1976},
  url = {https://ntrs.nasa.gov/citations/19760058410},
  note = {Source identifier: 19760058410}
}