@article{02100136,
title = {Variational calculus on sub-Riemannian manifolds.},
journal = {Balkan Journal of Geometry and its Applications (BJGA)},
volume = {8},
year = {2003},
pages = {21-32},
zbl = {1050.37031},
language = {en},
url = {http://dml.mathdoc.fr/item/02100136}
}
Călin, O.; Mangione, V. Variational calculus on sub-Riemannian manifolds.. Balkan Journal of Geometry and its Applications (BJGA), Tome 8 (2003) pp. 21-32. http://gdmltest.u-ga.fr/item/02100136/