%0 Journal Article
%A D. Z. Kagan
%T Invariant functions on free groups and special HNN-extensions
%J Čebyševskij sbornik
%D 2017
%P 109-122
%V 18
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/CHEB_2017_18_1_a6/
%G ru
%F CHEB_2017_18_1_a6