TY  - JOUR
AU  - U. Abresch
TI  - Isoparametric Hypersurfaces with Four or Six Distinct Principal Curvatures.  Necessary Conditions on the Multiplicities.
JO  - Mathematische Annalen
PY  - 1983
SP  - 283
EP  - 302
VL  - 264
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MAN_1983__264_163788/
ID  - MAN_1983__264_163788
ER  -