%0 Journal Article %A Karl Michael Schmidt %T On the essential spectrum of Dirac operators with spherically symmetric potentials. %J Mathematische Annalen %D 1993 %P 117-132 %V 297 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/MAN_1993__297_3_165121/ %F MAN_1993__297_3_165121