@article{MZ_1955__62_169503,
     author = {Friedrich Kasch},
     title = {Absch\"atzung der {Dichte} von {Summenmengen.}},
     journal = {Mathematische Zeitschrift},
     pages = {368--387},
     year = {1955},
     volume = {62},
     zbl = {0066.03102},
     url = {http://geodesic.mathdoc.fr/item/MZ_1955__62_169503/}
}