%0 Journal Article %A V. V. Volchkov %T Theorems on ball mean values in symmetric spaces %J Sbornik. Mathematics %D 2001 %P 1275-1296 %V 192 %N 9 %I mathdoc %U http://geodesic.mathdoc.fr/item/SM_2001_192_9_a1/ %G en %F SM_2001_192_9_a1