@article{costa_maciel_2003,  title={Combinatorial formulation of Ising model revisited},  volume={25},  ISSN={1806-1117},  url={https://doi.org/10.1590/S1806-11172003000100007},  DOI={10.1590/S1806-11172003000100007},  number={1},  journal={Revista Brasileira de Ensino de Física},  publisher={Sociedade Brasileira de Física - SBF},  author={Costa, G.A.T.F.da and Maciel, A. L.},  year={2003},  pages={49–61} }