@article{MZ_1939__44_168819,
     author = {H., Raff},
     title = {Minimumsprobleme f\"ur {Summen} absoluter {Betr\"age}},
     journal = {Mathematische Zeitschrift},
     pages = {452--480},
     publisher = {mathdoc},
     volume = {44},
     year = {1939},
     zbl = {64.0170.01},
     url = {http://geodesic.mathdoc.fr/item/MZ_1939__44_168819/}
}