%0 Journal Article %A David Blanc %T Homotopy operations and the obstructions to being an H-space. %J Manuscripta mathematica %D 1995 %P 497-516 %V 88 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/MM2_1995__88_1_156142/ %F MM2_1995__88_1_156142