@article{MAN_1974__210_162618,
     author = {Hubert Kalf},
     title = {Remarks on {Some} {Dirichlet} {Type} {Results} for {Semibounded} {Sturm-Liouville} {Operators.}},
     journal = {Mathematische Annalen},
     pages = {197--206},
     publisher = {mathdoc},
     volume = {210},
     year = {1974},
     zbl = {0297.34019},
     url = {http://geodesic.mathdoc.fr/item/MAN_1974__210_162618/}
}