@Article{ garpal05, author = { Garroni, Adriana and Palatucci, Giampiero }, title = { A singular perturbation result with a fractional norm }, journal = { Progress in NonLinear Differential Equations and their Applications }, year = { 2006 }, volume = { 68 }, pages = { 111-126 }, URL = { http://cvgmt.sns.it/paper/534/ }, note = { cvgmt preprint} }