%0 Journal Article
%A Kannappan, PL
%T A Functional Equation for the Cosine
%J Canadian mathematical bulletin
%D 1968
%P 495-498
%V 11
%N 3
%U http://geodesic.mathdoc.fr/articles/10.4153/CMB-1968-059-8/
%R 10.4153/CMB-1968-059-8
%F 10_4153_CMB_1968_059_8