@article{MS2_1966__19_165970,
     author = {Erik Balslev},
     title = {The {Singular} {Spectrum} of {Elliptic} {Differential} {Operators} in {Lp} {(Rn).}},
     journal = {Mathematica Scandinavica},
     pages = {193--210},
     publisher = {mathdoc},
     volume = {19},
     year = {1966},
     zbl = {0171.08501},
     url = {http://geodesic.mathdoc.fr/item/MS2_1966__19_165970/}
}