@article{lieb1961,
  title={Two soluble models of an antiferromagnetic chain},
  author={Elliott Lieb and T. D. Schultz and Daniel C. Mattis},
  year={1961},
  journal={Annals of Physics},
  doi={10.1016/0003-4916(61)90115-4},
  url={https://doi.org/10.1016/0003-4916(61)90115-4}
}