%0 Journal Article %T Abstracts of Theses %J Canadian mathematical bulletin %D 1968 %P 520-524 %V 11 %N 3 %U http://geodesic.mathdoc.fr/articles/10.1017/S0008439500029817/ %R 10.1017/S0008439500029817 %F 10_1017_S0008439500029817