%0 Journal Article %T Correction %J Canadian mathematical bulletin %D 1974 %P 429-429 %V 17 %N 3 %U http://geodesic.mathdoc.fr/articles/10.4153/CMB-1974-081-1/ %R 10.4153/CMB-1974-081-1 %F 10_4153_CMB_1974_081_1