%0 Journal Article
%A Xie, Guangheng
%A Yang, Dachun
%A Yuan, Wen
%T Pointwise Characterizations of Even Order Sobolev Spaces via Derivatives of Ball Averages
%J Canadian mathematical bulletin
%D 2019
%P 681-699
%V 62
%N 3
%U http://geodesic.mathdoc.fr/articles/10.4153/S000843951800005X/
%R 10.4153/S000843951800005X
%F 10_4153_S000843951800005X