@article{CMUC_1997__38_2_a22,
     author = {Kowalski, Old\v{r}ich and Vl\'a\v{s}ek, Zden\v{e}k},
     title = {On double-ruled hypersurfaces in $\bold R^4$},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {407--411},
     publisher = {mathdoc},
     volume = {38},
     number = {2},
     year = {1997},
     mrnumber = {1455509},
     zbl = {0891.53005},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1997__38_2_a22/}
}