@article{10_4171_ggd_13,
     author = {Indira Chatterji and Graham A. Niblo},
     title = {A characterization of hyperbolic spaces},
     journal = {Groups, geometry, and dynamics},
     pages = {281--299},
     year = {2007},
     volume = {1},
     number = {3},
     doi = {10.4171/ggd/13},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/ggd/13/}
}