@Misc{ biacav10, author = { Bianchini, Stefano and Cavalletti, Fabio }, title = { The Monge problem in geodesic spaces }, journal = { ``Nonlinear Conservation Laws and Applications", IMA Vol. Math. Appl., Springer, New York. }, year = { 2010 }, pages = { }, URL = { http://cvgmt.sns.it/paper/401/ }, note = { cvgmt preprint} }