1. For a complete and updated list of references, see the web site: tsallis.cat.cbpf.br/biblio.htm
2. C. Tsallis, Nonextensive Statistical Mechanics and Its Applications, Chap. Nonextensive Statistical Mechanics and Thermodynamics: Historical Background and Present Status, edited by S. Abe, Y. Okamoto (Springer-Verlag, Heidelberg, 2001)
3. J. Lorenzana, C. Castellani, C.D. Castro, Phys. Rev. B 64, 235127 (2001)
4. J. Lorenzana, C. Castellani, C.D. Castro, Phys. Rev. B 64, 235128 (2001)
5. A. Moreo, S. Yunoki, E. Dagotto, Science 283, 2034 (1999)