%0 Journal Article %A Beno Eckmann %A Urs Stammbach %A Peter J. Hilton %T On the Homology Theory of Central Group Extensions II. The Exact Sequence in the General Case %J Commentarii mathematici Helvetici %D 1972 %P 171-178 %V 47 %I mathdoc %U http://geodesic.mathdoc.fr/item/CMH_1972__47_139506/ %F CMH_1972__47_139506