%0 Journal Article %A W. Barth %T Irreducibility of the Space of Mathematical Instanton Bundles with Rank 2 and c2 = 4. %J Mathematische Annalen %D 1981 %P 81-106 %V 258 %I mathdoc %U http://geodesic.mathdoc.fr/item/MAN_1981__258_163580/ %F MAN_1981__258_163580