@article{mermin1966,
  title={Absence of Ferromagnetism or Antiferromagnetism in One- or Two-Dimensional Isotropic Heisenberg Models},
  author={N. David Mermin and Hermann‐Josef Wagner},
  year={1966},
  journal={Physical Review Letters},
  doi={10.1103/physrevlett.17.1133},
  url={https://doi.org/10.1103/physrevlett.17.1133}
}