@article{MZ_1922__12_167678,
     author = {E. Landau},
     title = {Zum {Waring'schen} problem},
     journal = {Mathematische Zeitschrift},
     pages = {219--247},
     publisher = {mathdoc},
     volume = {12},
     year = {1922},
     zbl = {48.0142.05},
     url = {http://geodesic.mathdoc.fr/item/MZ_1922__12_167678/}
}