%0 Journal Article %A Chua, Kok Seng %A Lang, Mong Lung %T Congruence subgroups associated to the Monster. %J Experimental mathematics %D 2004 %P 343-360 %V 13 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/EXMA_2004__13_3_52775/ %G en %F EXMA_2004__13_3_52775