@article{MZ_1940__46_168909,
     author = {E.-A., Behrens},
     title = {Bestimmung der {Stufe} f\"ur die aus bin\"aren {Thetareihen} erzeugten {Modulformen}},
     journal = {Mathematische Zeitschrift},
     pages = {350--374},
     publisher = {mathdoc},
     volume = {46},
     year = {1940},
     zbl = {0022.33301},
     url = {http://geodesic.mathdoc.fr/item/MZ_1940__46_168909/}
}