%0 Journal Article
%A Janusz Matkowski
%T Functional inequality characterizing nonnegative concave functions in (0, ?)k.
%J Aequationes mathematicae
%D 1992
%P 219-224
%V 43
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/AM2_1992__43_1_137465/
%F AM2_1992__43_1_137465