1. Quasi-geodesic segments and Gromov hyperbolic spaces;Bonk;Geom. Dedicata,1996
2. Uniformizing Gromov hyperbolic spaces;Bonk;Astérisque,2001
3. Embeddings of Gromov hyperbolic spaces;Bonk;GAFA,2000
4. Notes on Gromovs hyperbolicity criterion for path-metric spaces;Bowditch,1991
5. Metric Spaces of Non-positive Curvature;Bridson,1999