@article{MZ_1968__105_170993,
     author = {Johann Walter},
     title = {Bemerkungen zu dem {Grenzpunktfallkriterium} von {N.} {Levinson.}},
     journal = {Mathematische Zeitschrift},
     pages = {345--350},
     publisher = {mathdoc},
     volume = {105},
     year = {1968},
     language = {de},
     url = {http://geodesic.mathdoc.fr/item/MZ_1968__105_170993/}
}