%0 Journal Article %A P. Birtea %A J.-P. Ortega %A T. S. Ratiu %T A Local-to-Global Principle for Convexity in Metric Spaces %J Journal of Lie Theory %D 2008 %P 445-469 %V 18 %N 2 %U http://geodesic.mathdoc.fr/item/JOLT_2008_18_2_a12/ %F JOLT_2008_18_2_a12