TY  - RPRT
TI  - Multipair excitations and sum rules in interacting-electron systems.
AU  - F Green
AU  - D Neilson
AU  - D Pines
AU  - J Szymanski
PY  - 1987
DO  - 10.1103/physrevb.35.133
UR  - https://pubmed.ncbi.nlm.nih.gov/9940579/
ID  - 9940579
ER  -