1. Solvable subgroups of Out(Fn) are virtually Abelian;Bestvina,1997
2. Geodesics and curvature in metric simplicial complexes;Bridson,1991
3. The symmetries of outer space;Bridson,1999
4. Finite groups of automorphisms of free groups;Culler,1984
5. Moduli of graphs and automorphisms of free groups;Culler;Invent. Math.,1986