%0 Journal Article %A S. R. Kogalovskii %T On Birkhoff's theorem %J Trudy Matematicheskogo Instituta imeni V.A. Steklova %D 1965 %V 20 %N 5 %I mathdoc %U http://geodesic.mathdoc.fr/item/RM_1965_20_5_a11/ %G ru %F RM_1965_20_5_a11