%0 Journal Article
%A V. A. Bykovskii
%T Vahlen theorem for two-dimensional convergents
%J Matematičeskie zametki
%D 1999
%P 30-37
%V 66
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/MZM_1999_66_1_a3/
%G ru
%F MZM_1999_66_1_a3