@article{JRAM_1973__258_151282,
     author = {Bruno Ernst},
     title = {Ultra-(DF)-R\"aume.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {87--102},
     publisher = {mathdoc},
     volume = {258},
     year = {1973},
     language = {de},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1973__258_151282/}
}