@misc{indiciaea727bbc9051b,
  title = {Photon number amplification/duplication through parametric conversion},
  author = {Dariano, G. M. and Macchiavello, C. and Paris, M.},
  year = {1993},
  url = {https://ntrs.nasa.gov/citations/19940006117},
  note = {Source identifier: 19940006117}
}