%0 Journal Article
%A P. I. Lizorkin
%A S. M. Nikol'skii
%T Symmetric averaged differences on a sphere
%J Doklady Akademii Nauk
%D 1987
%P 271-274
%V 296
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1987_296_2_a2/
%G ru
%F DAN_1987_296_2_a2