%0 Journal Article %A Gareth Jones %T Enumerating Regular Maps and Normal Subgroups of the Modular Group %J Séminaire lotharingien de combinatoire %D 1986 %V 14 %I mathdoc %U http://geodesic.mathdoc.fr/item/SLC_1986_14_a5/ %F SLC_1986_14_a5