The image of the restriction map on 2-cohomology

J. L.Alperin, Sylow 2-subgroups of rank 3. In: Gainesville conference on finite groups, Shult, Gagen and Hale, eds., Amsterdam 1973.Google Scholar

G. W.Bell, Cohomology of degree 1 and 2 of some Chevalley groups. Ph. D. Thesis, The University of Michigan 1976.Google Scholar

J. Huebschmann, Sur les premières diffèrentialles de la suite spectrale cohomologique d'une extension de groupes. C. R. Acad. Sci. Paris285, Série A, 929–931 (1977).Google Scholar

S. Maclane andJ. H. C. Whitehead, On the 3-type of a complex. Proc. Nat. Acad. Sci. U.S.A.36, 41–48 (1950).Google Scholar

D. Quillen, On the cohomology andK-theory of the general linear groups over a finite field. Ann. Math.96, 552–586 (1972).Google Scholar

J. G.Ratcliffe, Crossed extensions to appear.Google Scholar

C.-H. Sah, Cohomology of split group extensions, II. J. Algebra45, 17–68 (1977).Google Scholar