@Article{ ambman96, author = { Ambrosio, Luigi and Mantegazza, Carlo }, title = { Curvature and Distance Function from a Manifold }, journal = { J. Geom. Anal. }, year = { 1998 }, volume = { 8 }, pages = { 723-748 }, URL = { http://cvgmt.sns.it/paper/1331/ }, note = { cvgmt preprint} }