1. Onsager, L.: The Ising model in two dimensions. In: Mills, R.E., Ascher, E., Jaffe, R.I. (eds.) Critical Phenomena in Alloys, Magnets, and Superconductors, pp. 3–12. McGraw-Hill, New York (1971)
2. Onsager, L.: Crystal statistics I. A two-dimensional model with an order-disorder transition. Phys. Rev. 65, 117–149 (1944)
3. Baxter, R.J.: Onsager and Kaufman’s calculation of the spontaneous magnetization of the Ising model. J. Stat. Phys. 145, 518–548 (2011)
4. Kaufman, B.: Crystal statistics II, partition function evaluated by spinor analysis. Phys. Rev. 76, 1232–1243 (1949)
5. Kaufman, B., Onsager, L.: Crystal statistics III. Short range order in a binary Ising lattice. Phys. Rev. 76, 1244–1252 (1949)