@Article{ monser01, author = { Monti, Roberto and Serra Cassano, Francesco }, title = { Surface measures in Carnot- Caratheodory spaces }, journal = { Calc. Var. Partial Differential Equations }, year = { 2001 }, volume = { 13 }, pages = { 339-376 }, URL = { http://cvgmt.sns.it/paper/1392/ }, note = { cvgmt preprint} }