TY  - RPRT
TI  - Four-loopndashorder beta function for two-dimensional nonlinear sigma models.
AU  - W Bernreuther
AU  - FJ Wegner
PY  - 1986
DO  - 10.1103/physrevlett.57.1383
UR  - https://pubmed.ncbi.nlm.nih.gov/10033435/
ID  - 10033435
ER  -