TY  - RPRT
TI  - Wick's theorem at nonzero temperatures.
AU  - M Revzen
AU  - JL Birman
PY  - 1994
DO  - 10.1103/physreve.49.2688
UR  - https://pubmed.ncbi.nlm.nih.gov/9961533/
ID  - 9961533
ER  -