@misc{indiciae1498a4d7ae24,
  title = {Extended Hubbard model in two dimensions.},
  author = {Y Zhang and J Callaway},
  year = {1989},
  doi = {10.1103/physrevb.39.9397},
  url = {https://pubmed.ncbi.nlm.nih.gov/9947675/},
  note = {Source identifier: 9947675}
}