%0 Journal Article
%A N. S. Romanovskii
%T Free subgroups of finitely-presented groups
%J Algebra i logika
%D 1977
%P 88-97
%V 16
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/AL_1977_16_1_a6/
%G ru
%F AL_1977_16_1_a6