%0 Journal Article %A S. M. Ageev %T Topological proofs of Keller's theorem and an equivariant version of it %J Izvestiya. Mathematics %D 1994 %P 621-629 %V 42 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/IM2_1994_42_3_a7/ %G en %F IM2_1994_42_3_a7