TY  - RPRT
TI  - Conservation sum rules for the quadratic density response function.
AU  - ZC Tao
AU  - G Kalman
PY  - 1990
DO  - 10.1103/physreva.42.6201
UR  - https://pubmed.ncbi.nlm.nih.gov/9903903/
ID  - 9903903
ER  -