%0 Journal Article
%A Robert Bieri
%A Burkhardt Renz
%T Valuations on free resolutions and higher geometric invariants of groups.
%J Commentarii mathematici Helvetici
%D 1988
%P 464-497
%V 63
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/CMH_1988__63_4_140130/
%F CMH_1988__63_4_140130