@Article{ MagMalMon12, author = { Magnani, Valentino and Malý, Jan and Mongodi, Samuele }, title = { A low rank property and nonexistence of higher dimensional horizontal Sobolev sets }, journal = { J. Geom. Anal. }, year = { 2015 }, volume = { 25 }, number = { 3 }, pages = { 1444–1458 }, URL = { http://cvgmt.sns.it/paper/2052/ }, note = { cvgmt preprint} }