@article{02175910, title = {Nonholonomic tangent spaces: intrinsic construction and rigid dimensions.}, journal = {Electronic Research Announcements of the American Mathematical Society [electronic only]}, volume = {9}, year = {2003}, pages = {111-120}, doi = {10.1090/S1079-6762-03-00118-5}, zbl = {1068.58001}, language = {en}, url = {http://dml.mathdoc.fr/item/02175910} }
Agrachev, A.; Marigo, A. Nonholonomic tangent spaces: intrinsic construction and rigid dimensions.. Electronic Research Announcements of the American Mathematical Society [electronic only], Tome 9 (2003) pp. 111-120. doi : 10.1090/S1079-6762-03-00118-5. http://gdmltest.u-ga.fr/item/02175910/