@article{PM_2006_2006_1_a13,
     author = {Rodr{\'\i}guez, Jos\'e M. and Tour{\'\i}s, Eva},
     title = {Una nueva caracterizaci\'on de la hiperbolicidad de {Gromov} para superficies de curvatura negativa.},
     journal = {Publicacions matem\`atiques},
     pages = {249-278},
     publisher = {mathdoc},
     volume = {50},
     number = {2},
     year = {2006},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PM_2006_2006_1_a13/}
}