TY  - RPRT
TI  - Nonlinear optics with less than one photon.
AU  - K J Resch
AU  - J S Lundeen
AU  - A M Steinberg
PY  - 2001
DO  - 10.1103/physrevlett.87.123603
UR  - https://pubmed.ncbi.nlm.nih.gov/11580512/
ID  - 11580512
ER  -