@misc{indiciaec364e5c2b9c1,
  title = {Derivation of a general expression for the momentum matrix elements within the envelope-function approximation.},
  author = {F Szmulowicz},
  year = {1995},
  doi = {10.1103/physrevb.51.1613},
  url = {https://pubmed.ncbi.nlm.nih.gov/9978880/},
  note = {Source identifier: 9978880}
}