TY  - RPRT
TI  - Dispersion relations and sum rules in nonlinear optics.
AU  - F Bassani
AU  - S Scandolo
PY  - 1991
DO  - 10.1103/physrevb.44.8446
UR  - https://pubmed.ncbi.nlm.nih.gov/9998799/
ID  - 9998799
ER  -