@article {2012,
	title = {On 2-step, corank 2 nilpotent sub-Riemannian metrics},
	journal = {SIAM J. Control Optim., 50 (2012) 559{\textendash}582},
	number = {arXiv:1105.5766;},
	year = {2012},
	publisher = {Society for Industrial and Applied Mathematics},
	abstract = {In this paper we study the nilpotent 2-step, corank 2 sub-Riemannian metrics\\r\\nthat are nilpotent approximations of general sub-Riemannian metrics. We exhibit optimal syntheses for these problems. It turns out that in general the cut time is not equal to the first conjugate time but has a simple explicit expression. As a byproduct of this study we get some smoothness properties of the spherical Hausdorff measure in the case of a generic 6 dimensional, 2-step corank 2 sub-Riemannian metric.},
	doi = {10.1137/110835700},
	url = {http://hdl.handle.net/1963/6065},
	author = {Davide Barilari and Ugo Boscain and Jean-Paul Gauthier}
}
