%0 Journal Article %A K.A. Jr. Perko %T On Dihedral Covering Spaces of Knots. %J Inventiones mathematicae %D 1976 %P 77-82 %V 34 %I mathdoc %U http://geodesic.mathdoc.fr/item/IM_1976__34_142388/ %F IM_1976__34_142388