@article{CMH_1949__22_138966,
     author = {Walter Nef},
     title = {Homogene {R\"aume} mit invarianter {Metrik.}},
     journal = {Commentarii mathematici Helvetici},
     pages = {215--231},
     publisher = {mathdoc},
     volume = {22},
     year = {1949},
     zbl = {0036.05203},
     url = {http://geodesic.mathdoc.fr/item/CMH_1949__22_138966/}
}