@article{JCA_2012_19_2_JCA_2012_19_2_a12,
     author = {A. Calogero and R. Pini},
     title = {c {Horizontal} {Convexity} on {Carnot} {Groups}},
     journal = {Journal of convex analysis},
     pages = {541--567},
     publisher = {mathdoc},
     volume = {19},
     number = {2},
     year = {2012},
     url = {http://geodesic.mathdoc.fr/item/JCA_2012_19_2_JCA_2012_19_2_a12/}
}