%0 Journal Article
%A V. V. Golovchanskii
%A M. N. Smotrov
%T On the spectrum of the Laplace--Beltrami operator for congruence subgroups of the modular group
%J Algebra i analiz
%D 2011
%P 31-39
%V 23
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/AA_2011_23_4_a1/
%G ru
%F AA_2011_23_4_a1