%0 Journal Article %A Griesemer, Marcel %A Lewis, Roger T. %A Siedentop, Heinz %T A minimax principle for eigenvalues in spectral gaps: Dirac operators with Coulomb potentials. %J Documenta mathematica %D 1999 %P 275-283 %V 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/DOCMA_1999__4__a10/ %G en %F DOCMA_1999__4__a10