@Misc{ AlbBiaCri12, author = { Alberti, Giovanni and Bianchini, Stefano and Crippa, Gianluca }, title = { On the L^p differentiability of certain classes of functions }, journal = { Revista Matemática Iberoamericana }, year = { 2012 }, pages = { }, URL = { http://cvgmt.sns.it/paper/1746/ }, note = { cvgmt preprint} }