@misc{indiciaebf09be6dfad7,
  title = {Envelope-function formalism for phonons in heterostructures.},
  author = {H Akera and T Ando},
  year = {1989},
  doi = {10.1103/physrevb.40.2914},
  url = {https://pubmed.ncbi.nlm.nih.gov/9992222/},
  note = {Source identifier: 9992222}
}