%0 Journal Article %A G. A. Kats %T On some characteristic classes in the category of smooth $G$-fiberings %J Sbornik. Mathematics %D 1971 %P 176-182 %V 15 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/SM_1971_15_2_a1/ %G en %F SM_1971_15_2_a1