@article{CMH_1985__60_140013,
     author = {Frederico Xavier},
     title = {A non-immersion theorem for hyperbolic manifolds.},
     journal = {Commentarii mathematici Helvetici},
     pages = {280--283},
     year = {1985},
     volume = {60},
     zbl = {0566.53045},
     url = {http://geodesic.mathdoc.fr/item/CMH_1985__60_140013/}
}