@article{MAN_1993__297_3_165121,
     author = {Karl Michael Schmidt},
     title = {On the essential spectrum of {Dirac} operators with spherically symmetric potentials.},
     journal = {Mathematische Annalen},
     pages = {117--132},
     publisher = {mathdoc},
     volume = {297},
     number = {3},
     year = {1993},
     zbl = {0796.35120},
     url = {http://geodesic.mathdoc.fr/item/MAN_1993__297_3_165121/}
}