@article{MAN_1975__217_162765,
     author = {Dirk Ferus},
     title = {Isometric {Immersions} of {Constant} {Curvature} {Manifolds.}},
     journal = {Mathematische Annalen},
     pages = {155--156},
     publisher = {mathdoc},
     volume = {217},
     year = {1975},
     zbl = {0295.53026},
     url = {http://geodesic.mathdoc.fr/item/MAN_1975__217_162765/}
}