@article{MZ_1931__33_168279,
     author = {G., Szeg\"o},
     title = {\"Uber einige neue {Extremaleigenschaften} der {Kugel}},
     journal = {Mathematische Zeitschrift},
     pages = {419--425},
     publisher = {mathdoc},
     volume = {33},
     year = {1931},
     zbl = {57.0573.03},
     url = {http://geodesic.mathdoc.fr/item/MZ_1931__33_168279/}
}