@misc{indiciae98324a2d6b16,
  title = {Four-loopndashorder beta function for two-dimensional nonlinear sigma models.},
  author = {W Bernreuther and FJ Wegner},
  year = {1986},
  doi = {10.1103/physrevlett.57.1383},
  url = {https://pubmed.ncbi.nlm.nih.gov/10033435/},
  note = {Source identifier: 10033435}
}