%0 Journal Article %A Mario J. Micallef %A Jon G. Wolfson %T The second variation of area of minimal surfaces in four-manifolds. %J Mathematische Annalen %D 1993 %P 245-268 %V 295 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/MAN_1993__295_1_165042/ %F MAN_1993__295_1_165042