%0 Journal Article
%A T.Y. Lam
%A Z.D. Dai
%T Levels in algebra and topology.
%J Commentarii mathematici Helvetici
%D 1984
%P 376-424
%V 59
%I mathdoc
%U http://geodesic.mathdoc.fr/item/CMH_1984__59_139983/
%F CMH_1984__59_139983