%0 Journal Article
%T A Letter to Professor J. Lambek
%J Canadian mathematical bulletin
%D 1969
%P 382-383
%V 12
%N 3
%U http://geodesic.mathdoc.fr/articles/10.1017/S0008439500030666/
%R 10.1017/S0008439500030666
%F 10_1017_S0008439500030666