@Article{ magsci10, author = { Magnani, Valentino and Scienza, Matteo }, title = { Characterizations of differentiability for h-convex functions in stratified groups }, journal = { Ann. Scuola Norm. Sup. Pisa Cl. Sci. }, year = { 2014 }, volume = { 13 }, pages = { 675-697 }, URL = { http://cvgmt.sns.it/paper/824/ }, note = { cvgmt preprint} }