%0 Journal Article
%A Cummins, C.J.
%T Congruence subgroups of groups commensurable with  of genus 0 and 1.
%J Experimental mathematics
%D 2004
%P 361-382
%V 13
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/EXMA_2004__13_3_52776/
%G en
%F EXMA_2004__13_3_52776