%0 Journal Article %A Kay Wingberg %T A Riemann-Hurwitz formula for the Selmer group of an elliptic curve with complex multiplication. %J Commentarii mathematici Helvetici %D 1988 %P 587-592 %V 63 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/CMH_1988__63_4_140135/ %F CMH_1988__63_4_140135