1. P. Ehrenfest, Proc. R. Neth. Acad. Arts Sci. 36, 153–157 (1933)
2. L.D. Landau, E.M. Lifshitz, Statistical Physics, 3rd edn. (Butterworth-Heinemann, Oxford, 1980)
3. J.-C. Tolédano, P. Tolédano, The Landau Theory of Phase Transitions (World Scientific, Singapore, 1987)
4. W. Lenz, Phys. Z. 21, 613–615 (1920)
5. E. Ising, Z. Phys. 31, 253–258 (1925)