@misc{indiciae6817c5cdee10,
  title = {Quantum-noise matrix for multimode systems: U(n) invariance, squeezing, and normal forms.},
  author = {R Simon and N Mukunda and B Dutta},
  year = {1994},
  doi = {10.1103/physreva.49.1567},
  url = {https://pubmed.ncbi.nlm.nih.gov/9910403/},
  note = {Source identifier: 9910403}
}