%0 Journal Article %A Udo Baumgartner %A Günter Schlichting %A George A. Willis %T Geometric characterization of flat groups of automorphisms %J Groups, geometry, and dynamics %D 2010 %P 1-13 %V 4 %N 1 %U http://geodesic.mathdoc.fr/articles/10.4171/ggd/72/ %R 10.4171/ggd/72 %F 10_4171_ggd_72