@misc{indiciae7ca73b9fb18d,
  title = {Sum-Frequency Generation from a Thin Spherical Layer: I. Analytical Solution},
  year = {2018},
  doi = {10.1134/s0030400x18060115},
  url = {https://www.osti.gov/biblio/22786404},
  note = {Source identifier: 22786404}
}