@article{MZ_1942__47_168964,
     author = {C., Carath\'eodory},
     title = {\"Uber das {Maximum} des absoluten {Betrages} des {Differenzenquotienten} f\"ur unimodular beschr\"ankte {Funktionen}},
     journal = {Mathematische Zeitschrift},
     pages = {468--488},
     publisher = {mathdoc},
     volume = {47},
     year = {1942},
     zbl = {0025.17103},
     url = {http://geodesic.mathdoc.fr/item/MZ_1942__47_168964/}
}