%0 Journal Article
%A Stothers, W. W.
%T Subgroups of infinite index in the modular group
%J Glasgow mathematical journal
%D 1978
%P 33-43
%V 19
%N 1
%U http://geodesic.mathdoc.fr/articles/10.1017/S0017089500003347/
%R 10.1017/S0017089500003347
%F 10_1017_S0017089500003347