%0 Journal Article %A Robinson, G. de B. %T A Remark by Philip Hall %J Canadian mathematical bulletin %D 1958 %P 21-23 %V 1 %N 1 %U http://geodesic.mathdoc.fr/articles/10.4153/CMB-1958-004-1/ %R 10.4153/CMB-1958-004-1 %F 10_4153_CMB_1958_004_1