@misc{indiciae08383d80b825,
  title = {Sum-frequency generation from photon number squeezed light},
  author = {Wu, Ling-An and Du, Cong-Shi and Wu, Mei-Juan and Li, Shi-Qun},
  year = {1994},
  url = {https://ntrs.nasa.gov/citations/19950007489},
  note = {Source identifier: 19950007489}
}