%0 Journal Article
%A Marica, J.
%A Schöheim, J.
%T Differences of Sets and A Problem of Graham
%J Canadian mathematical bulletin
%D 1969
%P 635-637
%V 12
%N 5
%U http://geodesic.mathdoc.fr/articles/10.4153/CMB-1969-081-4/
%R 10.4153/CMB-1969-081-4
%F 10_4153_CMB_1969_081_4