@article{MZ_1984__185_173403,
     author = {Andreas M. Hinz},
     title = {Obere {Schranken} f\"ur {Eigenfunktionen} eines {Operators} - ... + q.},
     journal = {Mathematische Zeitschrift},
     pages = {291--304},
     publisher = {mathdoc},
     volume = {185},
     year = {1984},
     zbl = {0513.35009},
     url = {http://geodesic.mathdoc.fr/item/MZ_1984__185_173403/}
}