@article{MM2_1975__17_154364,
     author = {H. Leinfelder and Ch.G. Simader},
     title = {Bemerkungen \"uber nichtlineare {St\"orungen} von {Schr\"odinger} {Operatoren.}},
     journal = {Manuscripta mathematica},
     pages = {187--204},
     year = {1975},
     volume = {17},
     zbl = {0323.35031},
     url = {http://geodesic.mathdoc.fr/item/MM2_1975__17_154364/}
}