@article{05381036,
title = {Differentiability of horizontal curves in Carnot--Carath\'eodory quasispaces.},
journal = {Sibirskij Matematicheskij Zhurnal},
volume = {49},
year = {2008},
pages = {67-86},
zbl = {1164.53344},
language = {en},
url = {http://dml.mathdoc.fr/item/05381036}
}
Greshnov, A.V. Differentiability of horizontal curves in Carnot–Carathéodory quasispaces.. Sibirskij Matematicheskij Zhurnal, Tome 49 (2008) pp. 67-86. http://gdmltest.u-ga.fr/item/05381036/