Phase diagram of a 2D Ising model within a nonextensive approach D. O. Soares-Pinto, I. S. Oliveira and M. S. Reis Eur. Phys. J. B, 62 3 (2008) 337-340 Published online: 19 April 2008 DOI: 10.1140/epjb/e2008-00170-5