@misc{indiciaec92c16fbbe19,
  title = {Dispersion relations and sum rules in nonlinear optics.},
  author = {F Bassani and S Scandolo},
  year = {1991},
  doi = {10.1103/physrevb.44.8446},
  url = {https://pubmed.ncbi.nlm.nih.gov/9998799/},
  note = {Source identifier: 9998799}
}