%0 Journal Article %T Openings in Mathematics %J Canadian mathematical bulletin %D 1964 %P 511-512 %V 7 %N 3 %U http://geodesic.mathdoc.fr/articles/10.1017/S000843950003215X/ %R 10.1017/S000843950003215X %F 10_1017_S000843950003215X