@Article{ alifocgel99, author = { Alicandro, Roberto and Focardi, Matteo and Gelli, Maria Stella }, title = { Finite-Difference Approximation of Energies in Fracture Mechanics }, journal = { Ann. Scuola Norm. Sup. Pisa Cl. Sci. }, year = { 2001 }, volume = { 4 }, number = { 29 }, pages = { 671-709 }, URL = { http://cvgmt.sns.it/paper/1406/ }, note = { cvgmt preprint} }