@Article{ catman09, author = { Catino, Giovanni and Mantegazza, Carlo }, title = { The evolution of the Weyl Tensor under the Ricci Flow }, journal = { Ann. Inst. Fourier }, year = { 2011 }, volume = { 61 }, number = { 4 }, pages = { 1407-1435 }, URL = { http://cvgmt.sns.it/paper/646/ }, note = { cvgmt preprint} }