%0 Journal Article
%A L. G. Kovalenko
%T Rate of approximation of functions by negative-order C\'esaro means of double orthogonal series
%J Izvestiâ vysših učebnyh zavedenij. Matematika
%D 2004
%P 72-75
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/IVM_2004_2_a8/
%G ru
%F IVM_2004_2_a8