%0 Journal Article %A Bynum, W. L. %T Weak Parallelogram Laws for Banach Spaces %J Canadian mathematical bulletin %D 1976 %P 269-275 %V 19 %N 3 %U http://geodesic.mathdoc.fr/articles/10.4153/CMB-1976-042-4/ %R 10.4153/CMB-1976-042-4 %F 10_4153_CMB_1976_042_4