%0 Journal Article %A V. L. Kurakin %T Periodic functions on a free semigroup %J Sbornik. Mathematics %D 2006 %P 1509-1528 %V 197 %N 10 %U http://geodesic.mathdoc.fr/item/SM_2006_197_10_a6/ %G en %F SM_2006_197_10_a6