We classify locally the induced Riemannian metrics of all irreducible double-ruled hypersurfaces in $\boldkey R^4$.
@article{118940, author = {Old\v rich Kowalski and Zden\v ek Vl\'a\v sek}, title = {On double-ruled hypersurfaces in $\bold R^4$}, journal = {Commentationes Mathematicae Universitatis Carolinae}, volume = {38}, year = {1997}, pages = {407-411}, zbl = {0891.53005}, mrnumber = {1455509}, language = {en}, url = {http://dml.mathdoc.fr/item/118940} }
Kowalski, Oldřich; Vlášek, Zdeněk. On double-ruled hypersurfaces in $\bold R^4$. Commentationes Mathematicae Universitatis Carolinae, Tome 38 (1997) pp. 407-411. http://gdmltest.u-ga.fr/item/118940/
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