@article{CMH_1964__39_139281,
     author = {J.R. Isbell},
     title = {Six theorems about injective metric spaces.},
     journal = {Commentarii mathematici Helvetici},
     pages = {65--76},
     publisher = {mathdoc},
     volume = {39},
     year = {1964},
     zbl = {0151.30205},
     url = {http://geodesic.mathdoc.fr/item/CMH_1964__39_139281/}
}