%0 Journal Article %A P. Hoffman %T Projective representations of $S_n$: ring structure and inductive formulae %J Banach Center Publications %D 1990 %P 289-297 %V 26 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/-26-2-289-297/ %R 10.4064/-26-2-289-297 %G en %F 10_4064__26_2_289_297