%0 Journal Article %A I. V. Artamkin %T Deforming torison-free sheaves on an algebraic surface %J Izvestiya. Mathematics %D 1991 %P 449-485 %V 36 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/IM2_1991_36_3_a0/ %G en %F IM2_1991_36_3_a0