A. Agrachev, Compactness for sub-Riemannian length minimizers and subanalyticity, Rend. Semin. Mat. Torino, vol.56, 1998.
DOI : 10.1051/cocv:1999114
URL : http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.614.7013

A. Agrachev, Quadratic mappings in geometric control theory, Journal of Soviet Mathematics, vol.15, issue.No. 2, pp.2667-2734, 1990.
DOI : 10.1007/BF01095430

A. Agrachev, Any smooth simple H 1 -local length minimizer in the Carnot-Caratheodory space is a C 0 -local length minimizer, 1996.

A. Agrachev and A. V. Sarychev, Strong minimality of abnormal geodesics for 2-distributions, Journal of Dynamical and Control Systems, vol.113, issue.2, pp.139-176, 1995.
DOI : 10.1007/BF02254637

A. Agrachev and A. V. Sarychev, Abnormal sub-Riemannian geodesics: Morse index and rigidity, Annales de l'Institut Henri Poincare (C) Non Linear Analysis, vol.13, issue.6, pp.635-690, 1996.
DOI : 10.1016/S0294-1449(16)30118-4
URL : http://doi.org/10.1016/s0294-1449(16)30118-4

A. Agrachev and A. V. Sarychev, On abnormal extremals for Lagrange variational problems, Journal of Mathematical Systems, Estimation, and Control, vol.8, issue.1, pp.87-118, 1998.

G. A. Bliss, Lectures on the calculus of variations, 1946.

B. Bonnard and M. Chyba, The role of singular trajectories in control theory, Math. Monograph

B. Bonnard and I. Kupka, Théorie des singularités de l'application entrée/sortie et optimalité des trajectoiressingulì eres dans leprobì eme du temps minimal, Forum Math, vol.5, pp.111-159, 1993.

B. Bonnard and I. Kupka, Generic properties of singular trajectories, Annales de l'IHP, Analyse non linéaire, pp.167-186, 1997.

B. Bonnard and E. Trélat, On the role of abnormal minimizers in SR-geometry, 1998.

B. Bonnard and E. Trélat, Stratification du secteur anormal dans la sph??re de Martinet de petit rayon, Nonlinear Control in the Year, 2000.
DOI : 10.1007/BFb0110218

H. Brezis, Analyse fonctionnelle, 1993.

R. L. Bryant and L. Hsu, Rigidity of integral curves of rank 2 distributions, Inventiones Mathematicae, vol.30, issue.no. 1127, pp.435-461, 1993.
DOI : 10.1007/BF01232676

M. R. Hestenes, Applications of the theory of quadratic forms in Hilbert space to the calculus of variations, Pacific Journal of Mathematics, vol.1, issue.4, pp.525-581, 1951.
DOI : 10.2140/pjm.1951.1.525

E. B. Lee and L. Markus, Foundations of optimal control theory, 1967.

C. Lesiak and A. J. Krener, The existence and Uniqueness of Volterra Series for Nonlinear Systems, IEEE Transactions on Automatic Control AC, vol.23, issue.6, 1978.

W. S. Liu and H. J. Sussmann, Shortest paths for sub-Riemannian metrics on rank-two distributions, Memoirs of the American Mathematical Society, vol.118, issue.564, 1995.
DOI : 10.1090/memo/0564

R. Montgomery, Abnormal Minimizers, SIAM Journal on Control and Optimization, vol.32, issue.6, pp.1605-1620, 1997.
DOI : 10.1137/S0363012993244945

M. A. Naimark, Linear differential operators, 1967.

L. Pontryagin, Théorie mathématique des processus optimaux, 1974.

A. V. Sarychev, The index of the second variation of a control system, Math. USSR Sbornik, vol.41, issue.3, 1982.

E. Trélat, Some properties of the value function and its level sets for affine control systems with quadratic cost, Journal of Dynamical and Control Systems, vol.6, issue.4, pp.511-541, 2000.
DOI : 10.1023/A:1009552511132

E. Trélat, Etude asymptotique et transcendance de la fonction valeur en contrôle optimal ; catégorie log-exp dans le cas sous-Riemannien de Martinet, 2000.

Z. Ge, Horizontal path spaces and Carnot-Carath??odory metrics, Pacific Journal of Mathematics, vol.161, issue.2, pp.255-286, 1993.
DOI : 10.2140/pjm.1993.161.255