%0 Journal Article %A Peter Li %A Andrejs E. Treibergs %T Pinching Theorem for the First Eigenvalue on Positively Curved Four Manifolds. %J Inventiones mathematicae %D 1982 %P 35-38 %V 66 %I mathdoc %U http://geodesic.mathdoc.fr/item/IM_1982__66_142867/ %F IM_1982__66_142867