@article{GDZPPN002371766, title = {Zum Sturm-Liouvilleschen Problem}, journal = {Mathematische Zeitschrift}, volume = {32}, year = {1930}, pages = {346-349}, zbl = {55.0259.02}, url = {http://dml.mathdoc.fr/item/GDZPPN002371766} }
Lichtenstein, L. Zum Sturm-Liouvilleschen Problem. Mathematische Zeitschrift, Tome 32 (1930) pp. 346-349. http://gdmltest.u-ga.fr/item/GDZPPN002371766/